Question

A and B together can do a piece of work in 12days;B and C together can do it in 15 days.
if A is twice as good as a workman as C;in how many days A alone will do the same work

Answer 1

Work done by (A+B) in one day = 1/12 Work done by (B+C) in one day = 1/15 subtracting both we get Work done by (A+B)-(B+C) = 1/12 -1/15 , Work done by (A-C) = (15-12)/12*15 = 3/12*15 = 1/60 we know that A is twice than C we get Work done by (A -1/2A) = 1/60 , now Work done by 1/2A = 1/60 => work done by A = 2/60 =1/30 So A can finish the work in 30 days

Answer 2

a can do the work in 30 days !!!