Question

4. 'A' can do a work in 10 days and 'B' can do the same work in 16 days. With the help of C they
do the work in 4 days only. In how many days 'C' can do the work alone?​

Answer 1

A's one day work= 1/10

B's one day work= 1/20

Let C's one day work=1/x

(A+B+C)'s one day work= 1/10 + 1/20 + 1/x

But it's given that they complete the work in 4 days. Hence their one day work will be 1/4

Therefore, (1/10 + 1/20 + 1/x) = 1/4

Solving for x, we get x = 10

Thus, C alone can complete the work in 10 days.