Question

A and B can complete the work in 30 days. A alone can complete the work in 40 days. B can complete the work in ​

Answer 1

A and B can do a piece of work in 30 days. It means A and B together do 1/30th part of the work in a day.

If B can do it, working alone, in 40 days, B does 1/40th of the work in a day.

Hence A does (1/30) - (1/40) = (4/120) -(3/120) or 1/120th part of the work in a day.

So A will take 120 days to do the work, working alone.

Check: (1/120) + (1/40) = (1/120)+(3/120) = 4/120 or 1/30 per day. Time taken by A and B together is 30 days. Correct.

A will take 120 days to do the work, working alone.

Hope this'll help you.