Question

Pearly and Peggy Sue left their dorm room at

the same time and headed in opposite directions.
After 9 hours they were 1,080 miles apart. If
Pearly drove 20 mph faster than Peggy Sue, how
fast did Peggy Sue drive?

Answer 1

50 mph

Explanation:

Distance = rate x time

Pearly

Distance = (r + 20)9

Peggy Sue

Distance = 9r

The distances add up t o 1080

(r+20)9 + 9r = 1080 Distribute the 9

9r +180 + 9r = 1080 Combine like terms

18r + 180 = 1080 Subtract 180 from both sides of the equation.

18r = 900 Divide both sides by 18

r = 50