what fraction of a pan of brownies did nicole and her friends eat?

Question

Nicole made two pans of brownies. she took 1/2 a pan of brownies to a meeting to share and put the remaining brownies in a container to save for later. the next day she and her friends ate 3/4 of the leftover brownies. what fraction of a pan of brownies did nicole and her friends eat? draw a model and write and solve an equation to justify your answer. explain your thinking.

Answer 1

Hi Stephanie,

 

This is a tough question that requires a lot of thinking . . . I'll try:

 

Nicole starts out with two pans of brownies.  If you divide each pan in half, there are two halves and two halves or four parts in total.  This means that each part was one fourth of the total.  If Nicole took 1/2 of one pan to her meeting, she took one fourth of the total and she put three fourths into a container for leftovers.

 

The next day she and her friends ate three fourths of the leftovers . . . that means 3/4 of 3/4.

 

"Of" generally means that you multiply. . . 3/4 X 3/4 = 9/16 of the total brownies.

 

But the question asks, "What fraction of one pan of brownies did they eat?"

 

One pan is half of two pans so the answer is half of 9/16 or 1/2 X 9/16 = 9/32

 

which is 3/4 X 3/4 X 1/2

 

The last part was my mistake.  I'll correct it. . .

If you think of each pan having 8 parts for a total of 16 parts, then 9/16 of two pans is 8 parts of the first pan and one part of the second pan which is 9/8 of one pan. . . the answer is 9/8

Answer 2

Initially Nicole made 2 pans of brownies, and took 1/2 pan of brownies to the meeting 

 

Leftover  =  2  -  1/2  = 4/2 - 1/2 = 3/2

 

Out of that she ate 3/4 of it with her friends i.e. 3/4(3/2) = 9/8 of a pan of brownies

 

9/8 of a pan of brownies she ate with her friends.