A train travels at the rate of 10 miles/hr for the first hour of a trip, at 20 miles/hr for the second hour, at 30 miles/hr for the third hour and so on. How many hours will it take the train to complete a 450-mile journey? Assume that the train makes no intermediate stops.
A. 8
B. 8.5
C. 9
D. 9.5
E. 10![]()
A. 8
B. 8.5
C. 9
D. 9.5
E. 10