Question
A man travels from town A to town B at 45 km/h and
returns from B to A at 30 km/h. If the distance between A and B is 120 km, find the total time taken for the round trip and his average speed.Solution
ATQ, Time A→B = 120 / 45 = 8/3 hours (2 h 40 min) Time B→A = 120 / 30 = 4 hours Total time = 8/3 + 4 = 8/3 + 12/3 = 20/3 hours (6 h 40 min) Total distance = 120 + 120 = 240 km Average speed = Total distance / Total time = 240 ÷ (20/3) = 240 × 3/20 = 36 km/h Answer: Total time = 6 h 40 min; average speed = 36 km/h.
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