Boats and Streams
Algebra
Level
2
A motorboat whose speed is 15 km/hr in still water goes 30 km downstream and comes back in a total of 4 hours 30 minutes.The speed of the stream (in km/hr) is:
The answer is 5.
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1 solution
Let v = speed of the stream from uniform motion formula Distance = VelocityxTime since Total time = 4.5hrs 4.5 = 30/(15+v) + 30/(15-v) v= 5