Question

A and b can do a piece of work in 20 days b and c can do a work in 30 days a and c can do the same in 40 days. What is the respective ratio of the number of days can a and c complete the same work

Answer 1

(A+B) = 20 days

(B+C) = 30 days

(C+A) = 40 days

LCM = 120 unit = let total work

Now ,

efficiency of (A+B) = 6

efficiency of (B+C) = 4

efficiency of (C+A) = 3

efficiency of (A+B+C) = (6+4+3)/2 = 6.5

so, efficiency of A = 6.5-4 = 2.5

and efficiency of C = 6.5-6 = 0.5

Number of days taken by A to complete whole work = 120/2.5 = 48

number of days taken by C = 120/0.5 = 240

Required ratio = 48:240 = 1:5 (ans.) ✍️☺️

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