jon starts out on a trip at 50mph. if 20 minutes later, joel starts out on the same route at 65mph, how long will it take joel to overtake jon? round to the nearest hour.

20 minutes = ⅓ of an hour, so Jon was ⅓ hr × 50 mi/hr = 50/3 mi out before Joel starts. 

Let t represent the time that Joel drove @ 65 mph 

Joel traveled t hr × 65 mi/hr = 65t mi 
Jon traveled 50/3 + 50t miles 

So 65t = 50/3 + 50t must be equal 

Solve for t to answer your question 

The answer is all about the number 4