ect answerA can complete a work in 12 days, B in 15 days. Find the time taken by them: If A leaves two days before the scheduled completion of the work.Options9 1/69 5/69 4/79 2/3

The problem is about work and time. Here are the steps to solve it:

Step 1: Find out how much work A and B can do in a day. A can complete the work in 12 days, so A can do 1/12 of the work in a day. B can complete the work in 15 days, so B can do 1/15 of the work in a day.

Step 2: Find out how much work they can do together in a day. A and B together can do (1/12 + 1/15) of the work in a day. This equals 9/60 or 3/20 of the work in a day.

Step 3: Find out when A leaves. A leaves 2 days before the work is completed. So, for those 2 days, only B is working. In 2 days, B can do 2 * (1/15) = 2/15 of the work.

Step 4: Subtract the work done by B alone from the total work to find out how much work A and B have to do together. The remaining work is 1 - 2/15 = 13/15.

Step 5: Find out how long it takes for A and B to do the remaining work together. They can do 3/20 of the work in a day, so it will take them (13/15) / (3/20) = 52/9 days to do the remaining work.

Step 6: Add the time B worked alone to the time A and B worked together to find out the total time taken. The total time taken is 2 + 52/9 = 70/9 = 7 7/9 days.

So, the time taken by them if A leaves two days before the scheduled completion of the work is approximately 7 7/9 days.