Question
A boat travels 315 km downstream
in 7 hours and 135 km upstream in 9 hours. Determine the total time the boat takes to cover 150 km upstream and 120 km in still water.Solution
ATQ, Downstream speed of the boat = 315/7 = 45 km/hr Upstream speed of the boat = 135/9 = 15 km/hr Speed of the boat in still water = (45 + 15)/2 = 60/2 = 30 km/hr Required Sum = (150/15) + (120/30) = 10 + 4 = 14 hours
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