Question
A man is travelling at a speed of 20 km/h such that he
will take 60 minutes to reach his destination. But after completing half the journey, the man took a break of 15 minutes and then continued his journey. Find the speed at which the man must cover rest of the journey to reach his destination in original time.Solution
Total distance to be covered = 20 × (60/60) = 20 km Time taken to cover half the distance at original speed = {(20 ÷ 2) ÷ 20} × 60 = 30 minutes Time remaining = 60 – 30 – 15 = 15 minutes Required speed = 10 ÷ 15 × 60 = 40 km/h
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