Pratik takes 8 hour to travel 36 km downstream and return to same spot .the speed of the boat in still water is 12 kilometre per hour find the speed of water current
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Let the speed of the stream be x km/h
Speed of boat downstream = (x + 12) km/h
Speed of boat upstream = (x - 12) km/h
time = distance/speed
Total time = 8 hours
Total time = 36 /(x + 12) + 36 / (x - 12) = 8
This is a quadratic equation giving value of:
x = 17.3 or x = - 8.3
(See the attached image)
We take the value of x = 17 because the speed of the water current can not be negative.
Speed of water current = 17.3 km/h
Speed of boat downstream = (x + 12) km/h
Speed of boat upstream = (x - 12) km/h
time = distance/speed
Total time = 8 hours
Total time = 36 /(x + 12) + 36 / (x - 12) = 8
This is a quadratic equation giving value of:
x = 17.3 or x = - 8.3
(See the attached image)
We take the value of x = 17 because the speed of the water current can not be negative.
Speed of water current = 17.3 km/h
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