Pkit wrote:

Yesterday it took Robert 3 hours to drive from City A to City B. Today it took Robert 2.5 hours to drive back from City В to City A along the same route. If he had saved 15 minutes in both trips, the speed for the round trip would be 60 miles per hour. What is the distance between city A and city B?

(A) 90

(B) 120

(C) 150

(D) 240

(E) 300

15 minutes less in each trip.

A to B, Actual time=3 hours; If 15 minutes saved, 2hours 45minutes i.e. t=2.75hours

B to A, Actual time=2 hours 30 minutes; If 15 minutes saved, 2hours 15 minutes i.e. t=2.25hours

\(Average \hspace{1} speed = \frac{Total \hspace{1} Distance}{Total \hspace{1} Time}\)

Let the distance between A and B be D.

\(Average \hspace{1} speed = \frac{D+D}{2.75+2.25}\)

\(60 = \frac{2D}{5}\)

\(D = \frac{60*5}{2} = 150 \hspace{1} miles\)

Ans: "C"

_________________

~fluke

GMAT Club Premium Membership - big benefits and savings