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A riverboat took 2 h to travel 24km down a river with the current and 3 h to make the return trip against the current. Find the speed of the boat in still water and the speed of the current.

Respuesta :

Speed of boat in still water = 10 km/hr

Speed of current of river = 2 km/hr

Explanation:

Let the speed of river be r and speed of boat be b.

Distance traveled = 24 km

Time taken to travel 24 km with current = 2 hr

We have

          Distance = Speed x Time

          24 = (b + r) x 2

          b + r = 12 --------------------eqn 1

Time taken to travel 24 km against current = 3 hr

We have

          Distance = Speed x Time

          24 = (b - r) x 3

          b - r = 8 --------------------eqn 2

eqn 1 + eqn 2

          2b = 20

            b = 10 km/hr

Substituting in eqn 1

            10 + r = 12

                     r = 2 km/hr

Speed of boat in still water = 10 km/hr

Speed of current of river = 2 km/hr

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