Problem: A train traveling from Aytown to Beetown meets with an accident after hr. It is stopped for hr., after which it proceeds at four-fifths of its usual rate, arriving at Beetown hr. late. If the train had covered miles more before the accident, it would have been just hr. late. The usual rate of the train is.
Answer Choices:
A. 20 mph
B. 30 mph
C. 40 mph
D. 50 mph
E. 60 mph
Solution:
.