Question

HELP:

Jerome and Ross each take two courses for summer school. Jerome takes a math course and a science course, while Ross takes a history course and a science course. For every 4 hours Jerome spends studying math, he studies science for 3 hours. For every 4 hours Ross studies history, he studies science for 2.5 hours.
If Jerome spent 16 hours studying math last week and Jerome and Ross studied science for the same amount of time, then Ross spent ___ hours last week.

Answer 1

He spent 12 hours studying science.

The ratio of time Jerome spends on math and science, respectively, is 4:3.  We know he spent 16 hours studying math last week, so our proportion looks like:

4/3 = 16/x

Cross multiply:
4*x = 3*16
4x = 48

Divide both sides by 4:
4x/4 = 48/4
x = 12

Since Jerome and Ross spent the same amount of time on science, then Ross also spent 12 hours on science.