Question 1197751
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Let the speed of the current be x; then the speed of the motorboat in calm water is 5x.  The upstream and downstream speeds of the boat on the river are then 4x and 6x.<br>
The ratio of the upstream and downstream speeds is 4x:6x = 2:3; the distance upstream and downstream are the same.  That means the ratio of times for the upstream and downstream trips is 3:2.<br>
The total trip takes 5 hours, so the upstream time is 3 hours and the downstream time is 2 hours.<br>
The round trip is 96km, so each leg is 48km.<br>
48km upstream in 3 hours means the upstream speed is 16km/hr.  But the upstream speed is 4x, so x = 4.<br>
ANSWER: The speed of the current is x = 4km/hr.<br>