Tough and Tricky questions: Distance/Rate.
On a reconnaissance mission, a state-of-the-art nuclear powered submarine traveled 240 miles to reposition itself in the proximity of an aircraft carrier. This journey would have taken 1 hour less if the submarine had traveled 20 miles per hour faster. What was the average speed, in miles per hour, for the actual journey?
A) 20
B) 40
C) 60
D) 80
E) 100
Kudos for a correct solution.