UPSTREAM
posted by CINDY on .
THIS EXURSION WITH A BOAT TRAVEL 35KM UPSTREAM AND THEN BACK AGAIN IN 4 H 48 MINUTRE. iF THE SPEED OF THE BOAT I5 K,/H, WHAT IS THE SPEED OF THE CURRENT?
Let v be the speed of the current. The boat's speed upstream (relative to the land) is 15v and the speed downstream is 15+v. The total trip time is
35/(15v) + 35/(15 + v) = 4.8 (hours)
Solve for the single unknown, v.

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