A car averages 30 miles per hour for the first 5 hours of a trip and averages 42 miles per hour for the rest of the trip. If the average speed for the entire trip is 34 miles per hour, how many hours long is the trip?	Select the correct option:
A) 6.5
B) 7.5
C) 8.5
D) 9.5
E) 10.5

Rationale: let t be the total time of the trip . 30 * 5 + 42 ( t - 5 ) = 34 t 8 t = 210 - 150 t = 7.5 the answer is b .
Answer: B