Try the following GRE quantitative reasoning question that tests your understanding of word problems based on distance, rate, and time relationship.
Question#101:
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?

$\quad \displaystyle \frac{3a+2mn}{120}$

$\quad \displaystyle 3a+2mn$

$\quad \displaystyle \frac{3a+2mn}{12}$

$\quad \displaystyle \frac{a+mn}{40}$

$\quad \displaystyle \frac{a+40mn}{40}$