Question

Mr. Yoshi has 75 papers. He graded 60 papers, and he had a student teacher grade the rest. What percent of the papers did each person grade?

Answer 1

Make a proportion to find Mr. Yoshi's percentage:
60/75 = x/100

Cross Products:
6000 = 75x
x = 80

So 60/75 = 80/100 which is 80%

Now for the student teacher:
The student teacher graded 75-60 = 15 papers.

Make a proportion:
15/75 = x/100

Cross products:
75x = 1500
x = 20
So 15/75 = 20/100 which is 20%

So Mr. Yoshi: 80%
Student Teacher: 20%

You can check by adding the two scores together and seeing if the sum is 100%:

80% + 20% = 100% 

It is, so the answer is correct.