Question
A boat travels faster than the stream by 28 km/h. It
covers a distance of 112 km upstream and returns 132 km downstream, all within 7 hours. Calculate the speed of the boat in still water, expressing your answer in meters per second.Solution
Let speed of stream = ‘x’ km/h Speed of boat = (x + 28) km/h Upstream speed = x + 28 – x = 28 km/h Downstream speed = x + x + 28 = ‘2x + 28’ km/h According to question; 112/28 + 132/(2x + 28) = 7 Or, 132/(2x + 28) = 3 Or, 2x + 28 = 44 Or, x = 8 Seed of boat = 8 + 28 = 36 km/h = 36 × 5/18 = 10 m/s Hence, option d.
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