A car traveled from San Diego to San Francisco at an average speed of 45 miles per hour. If the journey back took twice as long, what was the average speed of the trip?
Options:
(A) 30.
(B) 32.
(C) 36.
(D) 42.
(E) 44. Think first, then make a decision. Some random thoughts:
Let the time taken be = x
One way distance = 45x
Total distance traveled = 2 * 45x = 90x
Total time taken = x + 2x = 3x
Average speed = 90x/3x = 30 So the answer is (A).