A, B and C can do a piece of work in 20, 30 and 60 days respectively. In how many days can A do the work if he is assisted by B and C on every third day?Options12 days16 days18 days15 days

To solve this problem, we first need to find out how much work A, B, and C can do in a day.

1. A can finish the work in 20 days, so A can do 1/20 of the work in a day.
2. B can finish the work in 30 days, so B can do 1/30 of the work in a day.
3. C can finish the work in 60 days, so C can do 1/60 of the work in a day.

Next, we need to find out how much work A, B, and C can do together in three days.

1. In the first two days, only A is working, so the work done is 2 * (1/20) = 1/10.
2. On the third day, A, B, and C are all working, so the work done is (1/20) + (1/30) + (1/60) = 1/10.

So, in three days, they can do 1/10 + 1/10 = 1/5 of the work.

Therefore, to complete the whole work, it will take 5 * 3 = 15 days.

So, the answer is 15 days.

To solve this problem, we first need to find out how much work A, B, and C can do in a day.

1. A can do 1/20 of the work in a day.
2. B can do 1/30 of the work in a day.
3. C can do 1/60 of the work in a day.

Next, we need to find out how much work A, B, and C can do together in three days.

1. In the first two days, only A is working. So, in two days, A can do 2 * (1/20) = 1/10 of the work.
2. On the third day, A, B, and C are all working. So, in one day, they can do (1/20) + (1/30) + (1/60) = 1/10 of the work.

So, in three days, A, B, and C can do 1/10 + 1/10 = 1/5 of the work.

Therefore, to do the entire work, it would take them 5 * 3 = 15 days.

So, the answer is 15 days.