Question

A complete the work in 20 days, B in 30 days and C in 40 days. All started the work together. But after 5 days A left, After 3 days B left, C can complete the work in how many days?

Answer 1

Explanation:

A does 1/20 part of work in a day.

B does 1/25 part of work in a day.

C does 1/30 part of work in a day.

All will do (1/20+1/25+1/30=(15+12+10)/300 part of work=37/300 part.

In 3 days allot them do 3×37/300=37/100 part of work.

Remaining work=1–37/100=63/100.

A&B do 1/20+1/25 part of work=5+4/100=9/100.

Now 63/100 part has to be done by A&B

No of days taken by A&B=63/100÷9/100=63/100×100/9= 7 days.

Hence total days=3+7=10 days