Square root of 2 % of (5 times square root of 2) =? A BASIC Math problem MANY will get WRONG!

[@mikeo9863]

This video made a meal out of a simple problem. The key to percentages it to realise that percent mean per cent, per 100. So x% of y is just x*y/100

[@aryusure1943]

Yeahhhhhh! Got it! And I did the maths as well. :) Square root of 2 over 100 TIMES 5(square root of 2) over one. Second step: Numerator: Square root of 2 times 5(square root of 2) over denominator: 100 times 1 Third step: Numerator 5 times SR of 4 (SR of 2 times SR of 2) = 5 (SR of 4) = 10. Denominator = 100. Fourth step: Reducing the result i.e. 10/100 which equals 1/10 or .1 There you go.

[@robinblanc8208]

I’m taking one of ur courses now. I love it

[@panlomito]

I teach my students to change percentage into fraction: V2% = V2 / 100 so V2/100 x 5V2 = 5 . V2 . V2 / 100 = 10/100 = 0.1 so answer A

[@Kleermaker1000]

Of course that is the way to do it. 1% is simply 1/100. So 1% x sqr. 2 = 1/100 x sqr.rt 2/1 = sqrrt. 2/100.

[@russelllomando8460]

got it the hard way. sq rt 2 = 1.414 then solved. your solution was great, thanks. never thought of estimations, but with the answers being so diverse, it makes pure sense.

[@tomtke7351]

sqrt(2)×sqrt(2) = 2 2×5 = 10 (1E1) now to locate decimal point 1 percent = 0.01 (1E-2) 1E1 × 1E-2 = 1E(1-2) = 1E-1 = 0.1 => option a) ////// back in the day... before automobiles and electric light we used slide rules.... I did too. Slide rules were good for about 3 digits. Locating decimal was challenge /////

[@bigdog3628]

super simple no need for calculator or scrap paper. remember that x% is the same as x/100. Apply that here we got (√2)/100 * 5√2). now we got 5(√2 * √2) for the numerator and 100 in the denominator. √2 * √2 is √4 which is 2. Now we multiply 2 * 5 gives us 10. so final answer is 10/100 which reduces down to 1/10 or as he has it .1

[@angusmcpherson]

The difficulty I'm having is that when 2% is placed under a radical sign, it's the same as the sq. rt of .02, right? Therefore, if you take the square root of .02, you should be able to square the result and get the number under the radical sign. I find that when i do this with radical 2 over 100, (note that 100 is not under the radical, but outside it) i get 2 10 thousanths. Therefore answer a is incorrect, and answer b is the correct answer. The 100 in the denominator must be under a radical sign.

[@nickcellino1503]

No, the 100 in the denominator is NOT placed under the radical sign. It's √ 2/100 x 5 √ 2 = 5√ 4/100 = 10/100 =.1. I know it's a little confusing.

[@quigonkenny]

You're treating it as if it's √(2/100) when it's actually (√2)/100. The % is not under the root symbol. If it was, you'd be correct.

[@kdog3908]

Don't separate the root symbol from the 2. Treat the whole thing like it's a single thing. % just means **something** over 100 or **something** is that many parts of 100. Can be a variable, radical, whole number, complex number etc.

[@gopherspace8571]

Omg good stuff Mr math man 👍 ❤👋💪🌎

[@Rh11112]

The is over of statement should be stated as: 5 sq root of 2 is sq root 2% of what number? Correct?

[@krunoslavregvar477]

a) .1 absolutely

[@stevewthespider]

irrational percent of an irrational number is not useful in the real world

[@mollymam7153]

a) .1

[@safimoshkani8495]

Thank you It will be 0.1

[@terryjohinke8065]

The square root of 2 is an irrational number ( very important in music). thatx5 is 1.4144213... 5=0.7071065... and 2% of that is 0.14142... A very odd question with a poorly worded question.

[@btpcmsag]

a) 0.1

[@1961ebutuoy]

d

[@juergenilse3259]

sqrt(2)% does mean sqrt(2)/100, so sqrt(2)% of 5*sqrt(2)is the same as sqrt(2)/100*5*sqrt(2)=(sqrt(2)^2*5/100=10/100=10%. ou simpl hae to know the meaning of %: % is nothing else than /100 ...

[@kennethwright870]

a)

[@rodfulford4306]

=2*5/100 =0.1

[@jennymurray2873]

😮Good guess

[@fubaralakbar6800]

I solved it exactly the same way.

[@athletixbc]

You did not answer the question as written "Square root of 2 % of (5 times square root of 2) =? ". Instead you answered "Square root of 2 % times (5 times square root of 2) =? " .Two COMPLETELY different questions.

[@catherinewoodsellerbeckhor7560]

? Same thing in my book

[@gavindeane3670]

Those are exactly the same question. x% of y literally means (x/100)×y. That's the definition of percentage. So the problem statement here, when presented as a mathematical expression is √2 ------- × 5√2 100

[@givenfirstnamefamilyfirstn3935]

Writing the 5th root in the question doesn’t help.

[@oyesolaayobami6238]

A= 0.1

[@danluzurriaga6035]

.1

[@Ayelmar]

At the title card, only about 25% sure, but I'm going with a) .1

[@jald910]

A)

[@terry_willis]

I keep making the same mistake. I over complicate the problems. The solution turns out to be fairly simple. :( KISS as they say.

[@mawavoy]

A

[@quigonkenny]

√2 ≈ 1.4, so 5√2 ≈ 7 and √2% ≈ 1.4×0.01 = 0.014, so since 14(7) = 98, √2% of 5√2 ≈ 0.098 or 0.1. Not exact by any means (during the process, at least), but the possible answers are far enough apart that it clearly can only be a) 0.1. Interesting to note that the answer itself is exact, though.

[@alcoholfree6381]

Square root of 2 is 1.41. Fact. 5 times the square root of 2 is 7.05. Fact. So 1.41% of 7.05? Where is that wrong? Confusion.

[@athletixbc]

You are not the only one.. The way the question is worded "the square root of two percent of 5 times suare root of 2" it should be =sqrt((.02)(5sqrt2)) =sqrt((.02)(7.05)) =sqrt (.141) =0.375 The answer is not listed among the choices.

[@nickcellino1503]

I don't understand your confusion. 1.41% of 7.05 is approximately .1 which is the answer.

[@quigonkenny]

​@@athletixbcIt's not the square root of (2%), which is what you calculated (√0.02). It's (the square root of 2)% or roughly 0.014. For it to be the former, the root symbol must cover the %, which it does not.

[@gavindeane3670]

​@@athletixbcThat's not correct. For your interpretation, the horizontal line of the first radical symbol would have to extend over the length of the entire question, i.e. all of "% of 5√2" would have to be under the line. The only thing under the horizontal line of each radical symbol is the 2, so for both of them it is only the 2 that is being square-rooted.

[@EricWells-s2p]

​@@nickcellino1503The correct answer is exactly 0.1 There is no rationale for actually computing an approximation for the square root of +2.

[@marygiddings47]

Talk too much- boring

[@topkatz58]

Did it ever occur to you that this post may be addressing young students as well? So the reason why there is a long explanation. Besides your criticism will not change the video.