Crepe Problem

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by N:Dure » Sun Dec 05, 2010 11:31 am
for the 2nd problem: I did r2 for both

so 9:36 which is 1:4

so 10 crepes : 40 crepes

?

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by ikaplan » Sun Dec 05, 2010 1:56 pm
10 crepes * r1^2*pi=x crepes *r2^2*pi

10*6^2*pi=x*3^2*pi

10*36*pi=x*9*pi

x=40

IMO- C is the correct answer
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by N:Dure » Sun Dec 05, 2010 2:14 pm
Yep that's similar to what I did... my q is why r we using the area?

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by ikaplan » Mon Dec 06, 2010 1:19 am
In general, as you suggested, we should use the volume. However, the question states that "the new pancakes are with the same thickness" so author wants to say that you should ignore the "depth" of the crepes and thus consider them as 2 dimensional rather than 3 dimensional objects
"Commitment is more than just wishing for the right conditions. Commitment is working with what you have."