SOLUTION: It took Eric 11 hours to drive to a family reunion. On the way home, he was able to increase his average speed by 18mph and make the return drive in only 8 hpurs. Find his average
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Question 1109003: It took Eric 11 hours to drive to a family reunion. On the way home, he was able to increase his average speed by 18mph and make the return drive in only 8 hpurs. Find his average speed on the return drive. Answer by ikleyn(52809) (Show Source):
The "distance" equation
11*(r-18) = 8*r, (saying that the distance in both ways is the same)
where "r" is the average speed on the return drive (which is under the question).
11r - 11*18 = 8r ====> 11r - 8r = 11*18 ====> 3r = 11*18 ====> r = = 66.
Answer. The average speed on the return trip was 66 miles per hour.
