Question

a can do a piece of work in 20 days while B can do it in 15 days . With the help of C they finish the work in 5 days . In what time would C alone do it.
Hint-: A+B+C=5
A=20
B=15
(A+B+C) - (A+B) = C​

Answer 1

Answer:

C can complete the work alone in 12 days

Answer 2

Answer:

A does in one

A can do a piece of work in 20 days while B can do it in 15 days with the help of C. They finish the work in 5 days. In what time would C alone do it?

Consider 100% work to be done.

So A does : (100/20)% = 5% /day,

And B does:(100/15)% = 6.67% /day

Now given that , A+B+C together complete the work in 5 days.

So, A+B+C do : (100/5)% = 20% /day

now, in one day the work done by the above mentioned combinations:

=5% + 6.67% + C = 20%

=C = 8.33%/day

So if in one day C does 8.33% of the work, number of days required to complete 100% of the task will be

100/8.33 ≈ 12 days

hope it's helpful .me here miss_riyaaa