When Amy drives her car to work, the trip takes 1/2 hour. When she rides the bus, it takes 3/4 hour. The average speed of the bus is 12 mph less than her speed driving. Find the distance she travels to work.

Answer 1

X mi/h = Molly's speed.
(X-12)mi/h = Bus's speed.
Mary's distance and the bus's are equal:
d1 = d2
0.5*x = 0.75(x-12)
Multiply both sides by 4:
2x = 3x - 36
2x - 3x = -36
-x = 36
X = 36 mi/h.
d = V*t = 36 * 0.5 = 18 Mi.