Question

A is 50% as efficient as b. C does half the work done by a and b together. If c alone does the work in 40 days, then a, b and c together can do the work in how many days

Answer 1

Answer:

C is doing 100% work alone in 40 days; doesn’t it means that in one day he is doing 2.5 % work.

C is doing half the work done by A & B together; doesn’t it means that A + B together do 2.5%*2 = 5% work (Double of C’s one day work)

So (A + B + C)’s one day work is 5% + 2.5 % = 7.5 %

Doesn’t it means that together A, B & C do 7.5 % work in 1 day.

It means that they will do 100% work in 100%/ 7.5% = 1000/75 = 40/3 = 13.33 days