Denmark Math Olympiad Question

[@西が丘太郎]

This problem was asked as a entrance examination of famous high school in Japan more than 30 years ago. Denmark Math Olympiad Question is ・・・・・???

[@AsadbekIbadullaev-x4d]

Very good

[@samriddhisingh7783]

Please make video on science Olympiad questions...🥺

[@rizalsantos3658]

Can be written as 4/15...(lowest term)

[@88kgs]

That was easy , but very well explained

[@nikoskapitsos3110]

Very nice , but how i will guess that 224 is 2x4x7x4😂?

[@eunicesuisin4616]

Yeah your right .

[@twilighttulip868]

You can't factor numbers?

[@nikoskapitsos3110]

@@twilighttulip868 of course i can, but that wasn't something that it's very obvious.

[@backelie]

Well, you don't need to know that, all you need are the factors in the denominator. At that point you have 224 / (2*2*2*3*5*7). Divide by lowest factor -> 112/(2*2*3*5*7) -> 56 / (2*3*5*7) -> 28 / (3*5*7) -> 4 / (3*5)

[@cigmorfil4101]

Easy. 224 in decimal is the same as 0xe0 in hexadecimal = 0xe × 0x10 = 14x16 in decimal. Simples. Ok, so having programmed 8-bit computers in machine code by having to hand assemble the program I got to learn decimal to hexadecimal conversions between 0 and 255 (0x00 to 0xff), and my 16 times table, as well as the hexadecimal op code of most of the 6502 instruction set (in hexadecimal the various addressing modes to different op codes form regular patterns; 0xe0 = CPX #). ^_^

[@AsadbekIbadullaev-x4d]

Lklogic is the best

[@comfortablesofa]

Lovely!

[@evrankorkut8915]

teşekkürler

[@syedraza7277]

Y it is not 2x7,3x7.....

[@rizalsantos3658]

28/105

[@jannsteiner]

Which is 4/15.

[@rajug5709]

4/15

[@JohnHancockJr.-ck5sl]

Wasteful. You can simply divide both the denominator and the numerator by the cube of 7 without any prime factorization.

[@cigmorfil4101]

Not quite - you've prime factorised 14, 21, etc into 2×7, 3×7, etc and spotted the common prime 7; albeit in your head to spot the multiples of 7 in the numerator and denominator. She has done each step separately to clearly show what she is doing. The only prime factorisation she does is of 224 at the end. This can be done in conjunction with the denominator which is already in factors - divide the numerator by a factor of the denominator that divides it and see what's left.

[@Naifhasan555]

First cmnt