Carol started from home on trip averaging 30 miles per hour. How fast must her mother drive to catch up her in 3 hours if she leaves 30 minutes after Carol?
A. 35 m.p.h
B. 39 m.p.h
C. 40 m.p.h
D. 55 m.p.h
E. 60 m.p.h
It is a simple one, but the answer i get is 36. Maybe my calculation is wrong...
In 30 minutes (1/2hr) Carol drives 15 miles.
Relative speed is x-30, x being the rate of mother.
So (x-30)(3) = 15
Answer is A
Let the kudos rain begin!!