Fraction word problem

Question

Amanda used 1/3 cup of milk each time she makes a batch of pancakes. How many batches can she make if she has only 11/12 cup of milk left?

Answer 1

Hi Cindy,

 

What we need is a variable to represent the number of batches.  Let's call it B.

 

So each time she makes a batch, she uses 1/3 cut of milk.  To the amount of 

milk that she uses is (1/3)*B

 

We need to know when the amount she uses {(1/3)B} = the amount she has left to use (11/12 cup)

 

So the math equation would be

 

(1/3)B = (11/12)

 

IF you multiply both sides by 3, you will get B all by itself on the left.

 

(3)(1/3)B=(3)(11/12)

 

or 

 

B = 11/4 = 2.75

 

But one cannot make 0.75 of a batch, you either make a whole batch (when you have enough ingredients) or you don't make the pancakes.

 

So Amanda can make 2 batches, but she will not use up all of the milk.  She does not have enough milk to make 3 batches.