Question
A man rows 40 km upstream and 60 km downstream in 8
hours. If the ratio of his upstream speed to downstream speed is 2:3, then find the time required to travel 30 km upstream and 45 km downstream.Solution
ATQ,
Let the upstream and downstream speeds be 2x km/hr and 3x km/hr respectively. So, 40/2x + 60/3x = 8 = 20/x + 20/x = 8 = 40/x = 8 ā x = 5 Required time = 30/2x + 45/3x = 30/10 + 45/15 = 3 + 3 = 6 hours
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