Question
A’ and ‘B’ together can complete a work in 10
days, while ‘B’ and ‘C’ together can complete the work in 20 days. If ‘B’ takes 8 days to complete the work alone then find the time taken by all three together to complete 57.5% of work.Solution
Let the total work = 40 units Efficiency of (A + B) = 40/10 = 4 units/day Efficiency of (B + C) = 40/20 = 2 units/day Efficiency of ‘B’ = 40/8 = 5 units/day Efficiency of (A + B + C) = (4 + 2 – 5) = 1 units/day Required time taken = (0.575 × 40)/1 = 23 days
A boat covers a distance of 75 km downstream in 2.5 hours. If the ratio of upstream speed to downstream speed of the boat is 3:5, then find the distance...
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