Question

9. A and B can do a job together in 25 days. After 15 days of working together, B leaves. If A
completes the remaining part of the job in 20 days, how long would each take to complete
the job, working separately?​

Answer 1

Answer:

given,

A and B can do a job in 25 days,

(A+B)'s one day work = 1/25,

given,

A and B work together for 15 days,

so ,15/25 = 3/5 th work will be completed,

therefore,remaining work will be 2/5 th.

also given that,

A complete the remaining work in 20 days,

i.e,2/5 th work will be completed by A in 20days,

A alone complete the work in 20/(2/5) = 50 days.

A's one day work will be 1/50,

therefore,

(25/50)+(25/y) = 1,

=> (25/y) = 1 - (1/2),

=> (25/y) = 1/2,

=> y = 50.

therefore, B alone can do in 50 days,

A and B can do the work alone in 50 & 50 days respectively.

Hope it helps u...