Math for a test

Question

Lisa reads 15 pages in 10 minutes and wants to know how many pages she can read in 2 hours?

Answer 1

2 hours = 120 minutes

120/10 = 12. She can read 12 times as much

12 x 15 =180 pages

15/10 = x/120

3/2 = x/120

the ratios have to be the same, if you use the same units (minutes)

then cross multiply

2x = 360

x = 180 pages