Tough and Tricky questions: Distance/Rate.
On a reconnaissance mission, a state-of-the-art nuclear powered submarine traveled 500 miles to reposition itself in the proximity of an aircraft carrier. This journey would have taken 2.5 hour less if the submarine had traveled 10 miles per hour faster. What was the average speed, in miles per hour, for the actual journey?  Choose the correct choice from the following answers.
A) 40  B) 30  C) 60  D) 80  E) 100
Say, if speed is 40, 500/40 = 12.5 hrs and 500/50= 
<gadget id="calculator">500/50</gadget>
<output>10</output>
10 hrs (a reduction of 12.5 hr -&gt; Correct answer)   40nswer (40)
<result>A</result>
Tough and Tricky questions: Distance/Rate.
On a reconnaissance mission, a state-of-the-art nuclear powered submarine traveled 500 miles to reposition itself in the proximity of an aircraft carrier. This journey would have taken 2.5 hour less if the submarine had traveled 10 miles per hour faster. What was the average speed, in miles per hour, for the actual journey?