Question

11. A and B can together finish a work in 30 days. They worked at it for 20 days and then B left. The
remaining work was done by A alone in 20 more days. In how many days can A alone do it?​

Answer 1

Answer:

Work done by A and B together in 1 day = 1/30

A + B = 1/30 => B = 1/30 - A

A and B worked together for 20 days + A alone completed the remaining work in 20 days = whole work

(A + B )20 + (A )20 = 1

40A + 20( 1/30 – A) = 1

20A = 1 – 20/30

20A = 10/30

A = 1/60

A alone can finish the work in 60 days.