Question
P, Q and R can do some work in 11 days, 20 days and 55
days respectively. In how many days can the work be done, if P gets the assistance of Q and R on alternate days?Solution
Let, total work = (LCM of 11, 20, and 55) = 220 efficiency of P = 20 units Efficiency of Q = 11 units Efficiency of R = 4 units Work done by P and Q in first day = 20 + 11 = 31 Work done by P and R in second day = 20 + 4 = 24 Total work done by P, Q, and R in 2 days = 31 + 24 = 55 55-unit work done by all three in = 2 days Β 220-unit work done by all thee in = [2/55] Γ 220 = 8 days.
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