Sunday, February 12, 2006

Favorite puzzles

I'm going to start posting some of my favorite puzzles.

Puzzle 1:
Let's say you have a cup of cream and a cup of coffee (same volume). You take a spoon full of cream and mix it in with the coffee. Now, you take a spoon full of the mixed coffee/cream and and mix it with the cream. Is there more coffee in the cream cup or is there more cream in the coffee cup?

5 Comments:

Blogger pooya said...

more cream in the cream cup?

11:19 PM  
Anonymous Anonymous said...

I think they'd be equal too.

9:25 AM  
Anonymous Anonymous said...

Yup same amount. Assume the you start with 40 parts of Cream(X) and 40 parts of Coffee(Y).

And assume that the spoon transfers 10 parts of the liquid. Yes, it's a huge spoon. :)

40X and 40Y

Transfer 10X
30X and 40Y + 10X

Transfer 10 Part i.e 1/5 of 40Y + 10X
i.e. Transfer 8Y + 2X
32X + 8Y and 32Y + 8X

9:09 AM  
Blogger pooya said...

Hmm, I remember something about liquid in liquid solution and that the total volume of X in Y will be less than X+Y. I thought that's the point of the question assuming that spoon size is much smaller than the size of the cup. So I assumed 10 Parts of 40Y+10X is 1/4 not 1/5:

(40X,40Y)
(30X,40Y+10X)
(31X+10Y,30Y,9X)

8:34 AM  
Anonymous Anonymous said...

looks preatty difficult

10:02 AM  

Post a Comment

<< Home