If it cost Mary 25 holiday cookies for $15 , then how many cookies can she bake for $27?

Question

If it cost Mary 25 holiday cookies for $15 , then how many cookies can she bake for $27?

Answer 1

This question is an example of a simple proportion problem.  

 

We know that 25 cookies cost $15.  We want to know how many cookies cost $27.

 

So, we set up the proportion like this:

 

25/15 = x/27 where x is the unknown number of cookies.

 

Cross-multiplying, we get:

 

15x = 25 * 27 => 15x = 675 => x = 675/15 => x = 45

 

So, 45 cookies cost $27.