SOLUTION: Anna drove to her mother's house in two and a half hours. The next day because of traffic conditions her speed was about 18 km/h slower and consequently it took her three hours to

Question 1075558: Anna drove to her mother's house in two and a half hours. The next day because of traffic conditions her speed was about 18 km/h slower and consequently it took her three hours to drive home. What was her average speed driving home?
Answer by josgarithmetic(39617) (Show Source): You can put this solution on YOUR website!

:
             SPEED    TIME   DISTANCE
TO            r+18    2.5     d
FROM          r       3       d

---------Just solve this for r.
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