Question
Speed of current is equal to 40% of speed of boat in
still water. If the boat takes 5 hours to cover 80 km in still water, then find the time taken by the boat to cover 96 km in upstream.Solution
Speed of the boat in still water = 80 ÷ 5 = 16 km/h Speed of current = 16 × 0.4 = 6.4 km/h Therefore, upstream speed of the boat = 16 – 6.4 = 9.6 km/hr Required time taken = 96 ÷ 9.6 = 10 hours
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