Question

A can do a piece of work in 24 days, A and B can do it in 16 days and A, B, and C in `10 2/3`  days. In how many days can A and C do it working together?

Answer 1

A can do a piece of work in = 24 days

(A+B) can do a piece of work in = 16 days

(A+B+C) can do a piece of work in

`=10 2/3`days = `32/3` days

∴ A's 1-day work =`1/24`

(A+B)'s 1 day work =`1/16`

(A+B+C)'s 1 day work =`3/32`

C's 1 day work =`3/32-1/16`

`=(3-2)/32=1/32`

(A+C)'s 1-day work =`1/24+1/32`

`=(4+3)/96=7/96`

∴ (A+C) can do the work in =`96/7` days

`=13 5/7` days