Question 1155855
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If the average speed is 50 mph during the 3-hours trip, then the total distance is  (2+1)*50 = 150 miles.


In 2 hours, he just covered 2*40 = 80 miles.


Hence, he should cover the rest  150-80 = 70 miles in the last, third hour.


<U>ANSWER</U>.  He should drive at 70 mph.
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