How can the answer be exactly 25? Reddit algebra proportion r/askmath

[@wirelessbaguette8997]

If any one is interested, the answer could be exactly 20 (from the typo) if every newspaper is instead read by 75 students.

[@deltalima6703]

I dont think so, I think the students only read 4 newspapers. They just looked at the comics in the other one.

[@shaurryabaheti]

Hahahaha @@deltalima6703

[@Chessplayer81837]

​@@deltalima6703?

[@dddaaa6965]

I couldn’t understand because I thought each student read 5 newspaper meant they all read the same 5

[@amanda-we9fv]

SAME

[@main4066]

Thanks for making these kinds of videos!! I have dyscalculia which affects me severely so I've always struggled with math. I'm finished with school and managed to get a good enough grade in it (with lots of hard work!!) to get into my degree but it's a huge source of anxiety and shame for me. The thing is, I realized that I actually can find maths fun. I love the problem solving aspect of it! It's literally just that my brain jumbles things up so badly it often doesn't make sense at all. The way you go through things simplifies them in such a great way that I can understand even if I can't really do much with the numbers myself. Thank you! I wish you'd have been around when I was in school but either way I love your videos :-)

[@bprpmathbasics]

Thank you so much for your nice comment and I am very happy to hear it. Cheers and best wishes!

[@violetfactorial6806]

For people who get confused by the abstractness of the first solution, this could be a good lesson in dimensional analysis. We can invent a unit called the "student-newspaper" that represents a unique reading of a newspaper by a student. So for instance if we had 2 students and each reads 7 newspapers, that's 14 student-newspapers. Even though it's an abstract unit, it still has meaning. The first sentence tells us that there are 300 * 5 student-newspapers. The second sentence tells us that there are N * 60 student-newspapers (where N is the number of newspapers). The number of student-newspapers at the college doesn't change, so we can set these two expressions to be equal and solve the equation for N.

[@Ruija27]

Am I "underthinking" the logic here? 300 students * 5 reading sessions is 1500. Divide by 60 and you get 25. Easy?

[@jan_Mamu]

same

[@scragar]

Easier to start with the divide by 60. 300 students, each paper is read by 60, so 300/60 = 5 is the number of newspapers required for every student to read exactly one. Since every student reads 5 papers, we must need 5 times as many as our previous figure so 5×5=25 papers in total. Smaller numbers are a lot easier to work with than 1,500/60.

[@sinom]

Easy to calculate but might take people a while to figure out and rationalize that it is correct. Since the "unit" of 1500 is a bit unintuitive (basically "times any newspaper was read").

[@brianhsu_hsu]

I do this exactly the same. First get the reading session then divide it by 60.

[@rouelejour4080]

Five newspapers per sixty students. 5(300/60)=25.

[@AsuranFish]

I was confused by this because I thought “every newspaper is read by 60 students” meant “60 of the 300 students are reading every single newspaper”

[@SomewhatLazy]

What else would it mean?

[@CurryMuncher2]

@@SomewhatLazyeach newspaper is read by 60 students

[@boredomgotmehere]

I like the way you frame your “mathematical thinking” which gives you and your viewers, I suppose, the clarity to understand this.

[@ElijahLPlus]

I was confused at the wording because I thought: *_every newspaper ≠ each newspaper_* And that *_every newspaper = all newspapers_* But "each" and "every" are interchangeable in this context. This made it clearer for me: In a college of 300 students, every *_individual_* student reads 5 newspapers and every *_individual_* newspaper is read by 60 students.

[@naziaparveen2516]

Very nice! I was a bit confused at first,but the solution turned out to be relatively simple. You're a great teacher!

[@casusbelli9225]

Because you need to calculate the unit that is a product of metrics (as opposed to, for example, speed, which is the result of division between distance and time) Basically, you multiply students and how many newspapers they read, resulting in 1500 student-newspaper uints. Then you divide that number by how many students read one newspaper, resulting 1500/60 = 50/2 = 25. Which will be the number of newspapers. Similar approach is used when calculating energy consumption (you multiply device power consumption on the hours it worked) and in calculating effort (amount of people * time they spend working). Hence, i used to call these types of problems "the kilowatt-hour problem".

[@Flukeworm]

Respected sir, Find the value of the following questions geometrically in the principle value range: (a) arcsin(sin23) (b) arcsin(sin24) Where both 23 and 24 are in radians.

[@derwolf7810]

Given some comments here, i'm not sure if everyone has noticed that there is an implied restricted consumable good, which is the number of read operations. It might be helpful to slightly reformulate the task: In a college of 300 students every student performs 1 read operation per newspaper on 5 newspapers & every newspaper provides 1 read operation per student for 60 students. Then the answer (including shorter alternative approaches) is: 300 students * (1 readOperations / (1 newspapers) * 5 newspapers) / (1 students) / ((1 readOperations / (1 students) * 60 students) / (1 newspapers)) = 300 students * 5 readOperations/students / (60 readOperations/newspapers) = 300 students * 5 newspapers / (60 students) = 300 / 60 * 5 newspapers = 25 newspapers

[@thepuzzlesphinx]

exactly this guy needs to proof read his own problems before going to youtube

[@Vanhaomena]

The unintuitive part here is that no matter how they share the newspapers ends up not mattering at all. They'll still always need at least 25, but never need more than 25, so that is the unique and right answer. Proof by trust me bro, I tried to find a way for them to optimize the way they share the papers and failed miserably!

[@ultralaggerREV1]

The problem here is how can we approach such word problems. The English wording can confuse literally everyone. Like, there is one easy correct METHOD to solve the problem, but people are gonna be trying thousands of different methods and get it wrong. So how can we approach this problem and get it right at the FIRST try?

[@thepuzzlesphinx]

by having an expression instead of someone who isnt even a native speaker try to invent a word problem for click bait

[@Golgo1412]

​@thepuzzlesphinx this is so dumb... seems like native English speakers don't understand basic english

[@Therealfrogius]

I got exactly 25. but it's unrealistic for a college to have only 25 newspapers in circulation.

[@peachesHurst-vq5xn]

For anyone wondering, the answer is 6. I had to look it up because everyone was making it more complicated than it actually is lol

[@sorryboss8550]

I didn’t tap on the video, tried solving through the thumbnail alone and always ended up on 25, eventually I gave up and tapped on the video. I done wasted so much time😔

[@bprpmathbasics]

That typo confused me so much when I first saw that on Reddit. 😆

[@yetterkor6425]

same lol

[@yetterkor6425]

I sat there before clicking the video trying to figure out from the thumbnail and title how it could be anything other than 25 🤦‍♂️

[@zachansen8293]

1:50 no, it can't, because each student reads 5. It can only satisfy 12. (and technically not even that but the math still works) so if I newspaper can satisfy 12 then 25 can satisfy 300.

[@oenrn]

Divide the 300 students into 5 groups of 60. Each student in a group reads the same 5 newspapers, which are not read by any other group. So 5 groups of 5 newspapers each = 25 newspapers. You can then get different distributions by swapping newspapers between the students as many times as you want while the total number of 25 remains.

[@VedantSinha-g3p]

Set theory question

[@jamescollier3]

I can follow him using Feynman's integration technique, but this was hard. More coffee needed??

[@sauronblack9197]

You are not alone. Permutation and combination was one area I never got a hang of. I'll remember this answer until tomorrow, and then it'll simply disappear into the ether.

[@cokxi]

probability and p&c have always been counterintuitive to me as well, i feel like ove understood it, but nope, when i try to do any question i never get it on the first try.

[@Firefly256]

@@cokxiand you never know if the answer you got is correct, unless you already know the correct answer, unlike algebra where you can just plug the number back and check, or differentiating the answer when you are solving an integral

[@kavinesh_the_legend]

​@@cokxisame here 😂😂

[@HistoryChef]

@bprp math basics , This can also be done through the unitary method, if 60 students read 1 newspaper, 1 student reads=1/60 newspapers (WOW) and then 1500 reading sessions, so in that case, 25 newspapers.

[@keithhowen9493]

I just realized that my initial approach to formulate the problem is waaaaay too convoluted after seeing all the other explanations. Let's denote the number of newspapers as x. Imagine a 300 by x matrix, M, where M_ij = 1 if student i reads newspaper j, and 0 otherwise. This setup leads to two constraints: each row sums to 5, indicating that every student reads 5 newspapers, and each column sums to 60, showing that each newspaper is read by 60 students. Notice that if such matrix exists then swapping rows or columns does not change the row & column sums (the constraints are preserved) To solve this, consider filling the top-left 60x5 submatrix of M with all ones. This action implies that the first 60 students read exactly 5 newspapers. Consequently, the top right 60x(x-5) submatrix will contain all zeros since each of these students already reads 5 newspapers, and similarly, the bottom left 240x5 submatrix will be zeros because the first 5 newspapers are already read by 60 students each. Now, focus shifts to the bottom right submatrix of M, which is of size 240x(x-5). The condition x-5 >= 5 must hold because each row (student) still needs to sum to 5, representing that every student reads 5 newspapers. However, x-5 cannot be exactly 5 since then the bottom right submatrix would be all ones, violating the constraint that each newspaper is read by only 60 students as it would imply these newspapers are read by 240 students. The process described is recursive in nature. When attempted manually, it becomes apparent that it's possible to insert five of these 60x5 submatrices following the algorithm. This leads to the equation x-20=5, solving to find that x equals 25.

[@kennethgee2004]

no there are 5. each student reads 5 news papers they are all the same newspapers

[@banker3417]

i was so confused, at first i thought 25 were false, because it was very obvious.

[@rennoc6478]

Same

[@jeromebuenoval7476]

25 . . . . . 300x5=1500/60=(50×3)/(2×3) =50/2=25 Universal Quantifier = every It is not logical to read 5 newspapers of the same type So we take for granted that 5 newspapers are of different types Lets do it backward 25 newspapers are read by 60 students = 1500 newspapers held Out of 1500 newspapers, there are 5 types of newspapers sorted as follows 1. Sunday Post 2. Tabloid 3. Magazine 4. Weekly Bulletin 5. Daily Times How many college students are reading the 5 newspapers? 1500/5=300 college students In a college of 300 students every student reads 5 newspaper and every newspaper is read by 60 students The number of newspapers is? Suggested process Claims to premises (statements given) Part1 1. Is there 300 students in college? Modifier size - 300 nature - college Common Noun1 - students Yes, We assume that there are (premise1) "300 college students" is true 2. Does every student reads 5 newspapers? quatifier size - every Common noun1 - students implied - reading Modifier size - 5 common noun2 - newspapers Yes, We assume that (premise2) "every students reads 5 newspapers" is true not every student |¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯| | every 300 students | | |¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯| | | | not reading | | | | _______________________ | | | | | /\ | | | | | | 5 / \ not 5 | | | | | | news /read\ news | | | | | | papers/ -ing \papers | | | | | |_______|________|_______| | | | |__________________________| | |_____________________________| Proof by Extraction/Inference from the diagram above (logically limited to "every 300 students" as the case in point (inside the circle), and disregarding "not every 300 students" as impossible to be the case for the context of the claims (outside the circle) comb1 every 300 students not reading 5 newspapers V & S (contradictory) comb2 every 300 students reading 5 newspapers V & S (confirmation) comb3 every 300 students not reading not 5 newspapers not V not S (out of context and form) comb4 every 300 students reading not 5 newspapers V not S Only comb2 is i. necessarily valid as to form (by warranting as true premise) From summary of premises noun1 noun2 student s newspaper n prem1 300s Xn prem2 ∀s 5n prem3 60s ∀n prem4 60s Xn We can infer the relation and proportion So IF ∀s = 5n ∀s=300s It is ii. reasonably sound as to context, where there are no doubt in mind, (by asserting as evidence or proof and as a true consequence) THEN (plug in the relationship) 300s=5n is true consequence (comb2 states-every 300 students are reading 5 newspapers is true no more no less) Part2 3. Do 60 students read every newspaper? modifier - 60 Common noun1 - students Implied - reading Modifier size - every common noun2 - newspaper Yes, We assume that (premise3) "60 students reads every newspaper" is true 4. Is X the number of newspapers read by 60 students? modifier size - X number of common noun2 - newspapers Implied - read by modifier size - 60 Common noun1 - students Yes, We assume that (premise4) "X newspapers read by 60 students" We infer the proportion that 60 out if 300 students read 5 out of X 60:300 as to 5:X 60/300 5/X 0.20 = 5/X 0.20X=5 X=5/0 20 X=25

[@bprpmathbasics]

😮

[@jeromebuenoval7476]

​@@bprpmathbasics Kudos to you, often watch your vids, from simple to hardest (i.e. "cannot compute" in Steph Hawk robotic tone) Thanks, you're very much appreciated

[@theeraphatsunthornwit6266]

It is so easy i was not sure since it appear on difficult channel😂

[@darandomguy8557]

Okay but if there’s 5 groups of 60 and each group gets 1 newspapers and they just pass off the newspapers to the other groups then you would have 300 students that have read 5 newspapers each and there was still only 5

[@darandomguy8557]

The only way I can understand this is if it refers to the type of newspapers needed as then it would be 25. As 60 students reads 5 types and the other 5 groups reads 5 types then you get 25 types of newspapers.

[@darandomguy8557]

In a realistic situation you would need 1500 newspapers of 25 types of different newspapers. As normal people wouldn’t go around passing 25 newspapers to different people to meet the quota.

[@mattiasvermeersch]

If all 60 students in the group of 60 each reads the newspaper, that newspaper will have been read 60 times already. So each of the 5 groups needs their own newspaper that will be read 60 times. There are 5 newspapers per group and 5 groups, so in total 25 newspapers.

[@Tacholoco]

300•5/60=25

[@zachansen8293]

You should have included units so that it was clear that the newspapers was the units of the answer. Really a missed opportunity to show how units can tell you that you've solved the problem correctly.

[@dougse-bike9770]

300/60=5, 5x5=25. The answer is 25 and I suck at algebra.

[@mickvonbornemann3824]

150/6 = 25

[@Bayonet1809]

e. at least 5

[@kusumakusuma9637]

no, if there are only 5 newspapers, than each newspaper will be read by 300 students.

[@Bayonet1809]

@@kusumakusuma9637Yes, but it wasn't specified that each student reads *only* 5 newspapers, but that they have read 5, which if they read 300 would still be true.

[@kusumakusuma9637]

​@@Bayonet1809 first, 'at least 5' is definitely wrong answer. Second, it said 'every student reads 5 newspapers', in present tense, the word only is unnecessary. If I say, I eat 5 apples, nobody should assume that I eat more than that just because I don't use the word only.

[@Bayonet1809]

@@kusumakusuma9637Good point - the use of the present tense in the question is wrong too, unless one believes that all 300 students are reading all 5 newspapers concurrently, in which case the answer would have to be 1,500 newspapers. So if I were to rephrase the question to remove ambiguity it would be: In a college of 300 students, every student has read exactly 5 newspapers, and every newspaper was read by exactly 60 students. How many newspapers were there?

[@Bayonet1809]

@@kusumakusuma9637But saying that you eat five apples still leaves the possibility that you may continue the sentence with '... and then I eat 5 more.' So the number of apples you eat cannot be less than five, but it may be more depending on whether you provide more information. Because you use the present tense one can not be sure that the situation is not still evolving, while if you used the past tense then it would be clear that the situation had concluded.

[@thusspokeshabistari]

Do they share the 25 copies of the 5 different newspapers among the 300 of them???

[@cgrooney9945]

So if it was 360 students, every student reads 5 newspapers and every newspaper is read by 60 students. What is the answer?

[@cgrooney9945]

The answer is 30.....but if you use second method it will not give you the correct his answer 1--- 60 ^ x5 ^ 5--- 300 (but we now have 360 students) This will still equate to 25 It only works if the numbers line up.

[@cgrooney9945]

The problem with this question and many others is they RELY ON TERRIBLE GRAMMAR. Its not actually a difficult math question, it is just very poorly worded. When the answer is made clear, its usually a "oh, that's what they meant" opposed to a "oh thats how its solved"

[@jasonpatterson8091]

Bad wording here. This question needs some "exactly" added. If a student reads six newspapers, they also read 5, so you can get answers between 5 (everyone reads the same 5 papers) and infinity (everyone reads an infinite number of papers).

[@resveries_]

i think you’re overthinking it xD technically yes you’re right, but the question doesn’t give you any reason to assume the students would be reading more than 5 newspapers (in that case, the question would probably say “every student reads AT LEAST five newspapers”) with problems like this, i find you generally wanna take everything at face value. it says 5 newspapers, no reason to assume it means anything different than exactly that-otherwise you’ll only make things harder for yourself lol

[@thepuzzlesphinx]

nope. math requires absolutes. this guy is making click bait @@resveries_

[@Bayonet1809]

Exactly, if each newspaper is read by, say, 300 students then also each is read by 60 students. Thus my answer would be 5 (assuming this is an optimisation question where we want the lowest number of newspapers). This is my problem with worded problems like this, that the wording is often not precise enough to lead to a clear answer, or sometimes it can also lead to a different answer to that which was intended. It makes me have to second guess the examiner.

[@nicholasscott3287]

Not gonna lie, I did the second method in my head to work out the answer.

[@Robert53area]

I did the second method, but I got there a different way. I knew we needed to solve for X which was the number of newspapers read. The known variable is the student body, we have 300 and 60. I decided 300 by 60, to get 5. We know we have 5 newspapers, so how many does each need to read is X. 5 times 5 is 25.

[@veejayroth]

WHY IS THIS NOT SIMPLY SOLVED AS 300*5/60? Why even bother adding "x"?

[@mariyamdhilawala4286]

I am falling in love with maths again ❤ Thanks to you

[@bprpmathbasics]

Thank you.

[@donsanjino]

Brilliant :)

[@kevinmerritt5179]

The wording is ambiguous. The first statement is "each student reads 5 newspapers" (we'll assume reading the same newspaper twice and reading more than 5 is not allowed). However, the second statement says every newspaper is read by 60 students...it does not say EACH INDIVIDUAL newspaper is read by EXACTLY 60 students. If I had 300 newspapers, 60 students could each read 5 different newspapers and the statement "every newspaper is read by 60 students" is still true regardless of what the remaining 240 students read.

[@knight0fdragon]

You may want to reread the question again.

[@theeraphatsunthornwit6266]

But if you interpret it that way, cant you also incorrectly interpret the first part as *every student (combine or not combined) read at least 5 newspaper.*

[@kevinmerritt5179]

I was just pointing out that the word 'every' should be replaced with word 'each'. In the first part, I could interpret 'every student' to mean 'each student' but could interpret 'every newspaper' as 'the group of newspapers as a whole' or 'all the newspapers'. I would not necessarily need to use the same interpretation for both statements.

[@knight0fdragon]

@@kevinmerritt5179 no, you can’t. “Every” means you must use each item in a group, it does not mean you get to group them as a whole and then select less than all items in said group.

[@knight0fdragon]

You have 2 conditions you must satisfy. Every student reads 5 newspapers. Every newspaper is read by 60 students. What those 240 other students do is absolutely important because they must satisfy the condition of reading 5 newspapers.

[@ThePROestRedn99]

Just equate the no. Of readings....which is constant here

[@SomewhatLazy]

The answer to the question as it is worded is not 25. There isn't enough information in the problem to solve it accurately. Every student reads 5 newspapers, but each student may read the same one as another student or may read entirely unique ones. If it takes 60 students to read all of the newspapers, we only know that at most there are 300 different newspapers. That is it. There isn't enough information to get 25.

[@hafrepo]

"Every newspaper is read by 60 students" and "every student reads 5 newspapers" The boundaries are clear, you can't go above 25 or you go above the number of students (300). Every newspaper that exists has to be read by 60 students and each student has to read 5 newspapers. So if you go above 25 papers, you have to increase the number of students to satisfy the 60 students condition, and then you're out of bounds. So there is enough information.

[@SomewhatLazy]

@@hafrepo The language of the question is simply bad. It should say, "In a college of 300 students every student reads 5 newspapers. Each newspaper is read by 60 students. How many newspapers are there?" The original question could be interpreted to mean that out of 300 students, a pool of 60 students read all of the newspapers. Meaning that with 60 students, it could be as many as 300 newspapers if each student read a unique one, or as few as 60 if each student only read 1 unique one. Language matters and this question is very poorly worded.

[@hafrepo]

​@@SomewhatLazy So it starts out "In a college of 300 students *every student reads* 5 newspapers" How do you get that to mean maybe only some students could be reading the newspapers? "and" "every newspaper is read by 60 students." If the number of newspapers is more than 25, some students would have to read more than 5 newspapers or there would have to be more than 300 students, which would break either of the first two conditions. If the number of newspapers is less than 25, not all 300 students could read 5 newspapers. A student cannot read an entirely unique paper, because that paper has to be read by 59 other students, again "every newspaper *is* read by 60 students" If there were 300 newspapers, and 300 students. How do you satisfy the conditions that "every newspaper is read by 60 students" and "every student reads 5 newspapers" Your wording is almost identical to the original question. How is changing the and to a period and the second every to an each a meaningful change?

[@hafrepo]

​@@SomewhatLazy Ok, so I realized why the second every could be an issue. I don't think it is when taken in context of the assignment, but I can see how it could be.

[@Iron_Sheep]

@@hafrepo No, you are given 300 students and that each student read 5 newspapers. The upper bound is 1,500 (300*5) newspapers read but there is actually no limit on the population of newspapers provided by the question.

[@JubeiKibagamiFez]

0:10 Okay.... Soooo, I'm probably reading this wrong, but I think the answer is D: None of the above. 300*5=1500 newspaper copies. Assuming 5=the number of newspaper publications, and every newspaper is read by 60 students. 60*5=300 students. So, is the answer how many physical newspaper copies are there or is it how many different publications are there, because what student or human for that matter is going to read 5 of the same newspaper???? Either way, any way, the answer is not 25 or 20 or 30 or anywhere in between 20 and 30.

[@byeguyssry]

(I assume you've watched the video by now, but I felt I should point out that D would only be the correct answer if the answer was between 21 and 29 but not 25. B is at most 20, so B is correct if it is between 0 and 20. And A is correct if it is 30 or more)

[@asdfqwerty14587]

Whether it's a physical newspaper or something else doesn't really change anything. Even if you interpreted it as an actual physical newspaper, then you're still saying that each newspaper was read by 60 students.. that would be very strange for 60 students to each read the exact same physical newspaper, but it wouldn't actually change the math at all. The only thing I can see that could be an ambiguity is the statement "every newspaper was read by 60 students" - you could argue that this should actually be interpreted as "at least 60 students" instead of being exactly 60 students (after all, if 300 people read a newspaper.. then it was also read by 60 people too). If you interpret that as being at least 60 students, then the answer would be "at most 25" (well, and also at least 5 because a student can't read 5 newspapers if there aren't 5 newspapers) instead of exactly 25.

[@JubeiKibagamiFez]

@@byeguyssry Okay. Nevermind. The answer is A because there are 1500 newspapers.

[@theeraphatsunthornwit6266]

Your 60x5=300 students is wrong because each student can read the same newspaper. 300 is the number of copies in this case.

[@JubeiKibagamiFez]

@@asdfqwerty14587 Okay, so, if the newspapers are being shared, then there are only 5 newspapers because each student reads 5 newspapers and each newspaper is read by 60 students and the 300*5 is irrelevant. All that matters is each newspaper, 5, gets read by 60 students, equals 300 students. So the answer is 5 newspapers/B. Again, I could be reading this wrong, I horrible at solving these types of math problems. I failed many tests because of these types of questions, but I still don't know where 25 comes from... And yes, I did watch the whole video.

[@mynameisbakr]

how did people get stuck on this???

[@matthewtallent8296]

I'm an advanced math person for sure, but my mom often asks questions like, "okay, but what is x?" Not understanding that the point of x is to be what the answer is. Many logical concepts in math don't click for certain people, especially when they spend their lives doing things unrelated to logic (my mom has always been a special needs assistant for young kids, and they are not taught algebra at such a young age)

[@siddhantnikam768]

there are people in the comments saying that answer should be 1500 or even 5

[@brrrrutale]

I mean, the math is not complicated but the problem is really badly formulated as it leaves too much room for interpretation.

[@thepuzzlesphinx]

not a good question, too many variables, no controls. this is why word problems are not good. stick to formulas. you can interpret this question at least 3 ways, and according to the braindeads in the comments you can interpret this 10000 ways people can share. you can have multiple students to 1 paper. assuming 1 paper to 1 student is NOT in the original problem. the answer is at least 20. not exactly 25.

[@club6525]

You assumed that each newspaper is different. Assuming each are the same, there can be only 5.

[@k-senpai3203]

no, if all 300 student read 5 same newspaper, then there would be 300pcs newspaper of each type. which contradict the second statement.

[@club6525]

@k-senpai3203 No, there is only 5 pcs. It's either digital or the whole school reads one copy in class.

[@k-senpai3203]

@@club6525 each student read 5 pcs. there 300 student and each of them read 5pcs. if one student read 1 copy of each type, then there should be 300 copies of each type... this is the case if 5 newspaper... so its contradict the statement

[@k-senpai3203]

the only assumption here is that 'each student didn't read the same newspaper for 5 times'​ @@club6525

[@Iron_Sheep]

@@k-senpai3203 It does not contradict the sentence. There is nothing in the second statement restricting that a newspaper has to be read only 5 times.

[@jumpman8282]

My first problem was to decipher the question. After that, my first thought was that it's a convoluted combinatorics puzzle, but then it dawned on me that the probability of getting one particular newspaper from a total of 𝑛 newspapers in 5 trials without repetition must be equal to 60 ∕ 300. From there, it was a piece of cake to find 𝑛. EDIT: Wow, I really overthought this one. All I needed to realize was that 60 students read newspapers 1-5, 60 read newspapers 6-10, etc.