Question

a can do a piece of work in 12 days and b can do the same work in 15 days he works alone for 4 test in how many days will a and b together finish the remaining work​

Answer 1

Answer:

31

Step-by-step explanation:

12 +15 is his total work so 12+15 =27 +4=31

Answer 2

Answer:

"A" and "B" will together finish the remaining work in (40/9) days or 4$\frac{4}{9}$ days.

Step-by-step explanation:

A can do the work in 12 days. Hence, in one day, A will finish 1/12 of the work

Similarly,

In one day, B can finish 1/15 of the work.

When they work together, the fraction of the work completed in one day is:

1/12 + 1/15 = 5/60 + 4/60 = 9/60 = 3/20

Thus, A and B working together can finish 3/20 of the work in one day.

We are given that A works alone for 4 days. The fraction of work that A can complete in 4 days = 4*(1/12) = 1/3

Hence after 4 days, 2/3 of the work remains.

We know that A and B together can complete 3/20 of the work in one day. If they have to complete 2/3 of the work in "x" days (say). Then:

(3/20) * x = (2/3)

x = (20*2)/(3*3)

x = 40/9

  = 4$\frac{4}{9}$