Challenging perimeter problem | Perimeter, area, and volume | Geometry | Khan Academy 

@A010795 Right, think of it as fraction. If we place 122 and 138 over 1, we can reduced them by 2, so there common divisor is 2. Another example is on from the addition of fractions, let x=3, then y=6/5. The only common divisor they have in common is 5.

@A010795 then their common divisor would be 2, W=122 - L=138. When the common divisor is 1, it's like asking what is the smallest sides can this rectangle be with the same proportions.

It's amazing how with only the given information, we can find out the exact dimensions of the rectangle

Reminds me of a stoichiometric problem in chemistry.

This is awesome. Thanks

I solved this on my own! But I spent way too long stuck at the end because for some reason I kept thinking the question's wording meant the length and the width had to be prime numbers. Of course when you solve it, you make it look like a piece of cake.

33 x 37 are also possible lengths/ widths if you do the problem a bit differently

The interesting follow up is to add up the area of all the squares which should equal the area of the rectangle. 4209 .......

beautifully done. Great.

@usmansharifmicky I asked the same question; but think about this. If you chose 10 and 4, the final answers would be divisible by 2, and the question asks for both numbers to have a common divisor of 1. So to answer the question properly you would still have to divide your numbers by 2 to get the same answer that you would get for 5 and 2.

WoW....Lots a FUN.....how solve reveals by itself...!!

@6freddyb ohh so no matter which integers you choose, you want the final answers to have a common divisor of 1?

What if you choose y to be 10 instead of 5?

Can u do more of these challenging problems ?? They're amazing !

9:03 *VERY NICE*

very nice

cool!

please make a video about the kissing number problem sal!

So you just guessed it would be 2 and 5, hmm. Honestly, isn't there a better way?

oh, ok, got it.

Huh, that was pretty interesting

.....but why did you choose to plug 5 in? You could have plugged anything else in....and might have had to guess for ages...

1337th view. This video is amazing

i figured most of it out myself, i just waited till he got started then went off on my own. It wasn't that hard.

Why Y is 5? I stopped in "pick a number time"

I hate myself for watching this. It would have been fun to find out for myself.

If you solve that x=2/5y, then can't you substitute 2/5y in for x in the equation 13x+7y=8x+9y? I got that x=2/5 and y=1, then subtituted both of those in each of the equations of the sides, and i got that the perimeter was 54. Did anyone else get that?

still confused .....can anybody help ??????

*non-overlapping

why is Y 5? and x 2

such easy questions appear in American mathematics aptitude exams? That's why the intelligence level of Indian students is far ahead as compared to American students.