A driver goes on a trip of 70 kilometers, the first 35 kilometers at 48 kilometers per hour and the remaining distance at 24 kilometers per hour. What is the average speed of the entire trip in kilometers per hour?
Choose the most appropriate option:
A) 30	B) 32	C) 35	D) 36	E) 40

Rationale: "the time for the first part of the trip was 35 / 48 hours . the time for the second part of the trip was 35 / 24 hours . the total time fro the trip was 35 / 48 + 35 / 24 = 105 / 48 = 35 / 16 hours . the average speed for the trip was 70 / ( 35 / 16 ) = 32 kph the answer is b ."
Answer: B