Question
The speed of a boat in still water is 20 km/h, and the
speed of the river flow is 4 km/hr. If the total time taken for the boat to go from point 'X' to point 'Y' and return is 12 hours, find the distance between point 'X' and point 'Y'.Solution
ATQ, Upstream speed = 20 - 4 = 16 km/h Downstream speed = 20 + 4 = 24 km/h Let the distance between points 'X' and 'Y' be 'd' km. Time equation: {(d/24)+(d/16)} = 12 Solving for 'd': 2d+3d=12×48 5d = 576 d=115.2 km Distance = 'd' = 115.2 km
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