Question

A can do a piece of work in 50 days, while B can do it in 40 days. They work at it

together for 5days and then A goes away. In how many days will B finish the

remaining work. Find the total number of days taken to complete the work.​

Answer 1

Answer:

11 days

Step-by-step explanation:

In one day A can complete 1/25 of the work. And.

In one day B can complete 1/20 of the work.

Together they can complete 1/25+ 1/20 work in one day.

Hence in 5 days they can complete 5/25 + 5/20 work. ie = 9/20 work.

Remaining work is 1–9/20 work= 11/20 work

Hence B can complete the remaining 11/20 work in 11/20 / 1/20=11 days.

Answer 2

Answer:

If A and B work alternatively for total 2 days (both individual worked for one day each), then {(1 / 40) + (1 / 50)} = (9 / 200) of total work gets completed.

But, 200 is not completely divisible by 9; the largest number completely divisible by 9 less than 200 is 198.

198 / 9 = 22

So, if A and B work alternatively total 22 days (both individuals worked for 11 days each), (198 / 200) of total work gets completed. The remaining (1 / 200) of total work will be done by A on the 23rd day in {24 * 40 / 200} hours = 4.8 hours = 4 hours 48 minutes.

So, A will work for 12 days and B will work for 11 days.