Question
‘R’ and ‘S’ together can finish a work in 25
days. If ‘R’ increases his efficiency by 60% and ‘S’ decreases his efficiency by 20%, then the time taken remains unchanged. Find the ratio of efficiencies of ‘R’ and ‘S’, respectively.Solution
Let the efficiency of ‘R’ and ‘S’ be ‘x’ units/day and ‘y’ units/day, respectively. So, total work = {(x + y) × 25} units After change in efficiencies, Also, total work = (1.6x + 0.8y) × 25 So,
1.6x + 0.8y = x + y Or,
0.6x = 0.2y Or,
x : y = 1 : 3 So, ratio of efficiency of ‘R’ and ‘S’ = 1 : 3
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