Problem: How many hours does it take a train traveling at an average rate of 40 mph between stops to travel a miles if it makes n stops of m minutes each?
Answer Choices:
A. 1203a+2mn
B. 3a+2mn
C. 123a+2mn
D. 40a+mn
E. 40a+40mn
Solution:
The train is moving for 40a hours and is at rest for nm minutes or 60n⋅m hours. ∴40a+60nm=1203a+2mn.