SOLUTION: It took Gina 1.8 hours to drive to her​ mother's house on Saturday morning. On her return trip on Sunday ​night, traffic was​ heavier, so the trip took her 2 hour

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Question 1070415: It took Gina 1.8 hours to drive to her​ mother's house on Saturday morning. On her return trip on Sunday ​night, traffic was​ heavier, so the trip took her 2 hours. Her average speed on Sunday was 4 mph slower than on Saturday. What was her average speed on Sunday​?
Answer by josgarithmetic(39614) About Me  (Show Source):
You can put this solution on YOUR website!
               SPEED      TIME     DISTANCE
GOING            r         1.8       d
RETURN          r-4        2         d


Same distance d both ways.
%28r%29%281.8%29=%28r-4%29%282%29------solve for r.