Question

A and B can do a piece of work in 15 days. B and C can do the same work in 30 days. A
and C need 18 days to complete the work. In how many days will C alone complete the
work?

Answer 1

Step-by-step explanation:

Given,

(A+B+C) can do a piece of work in = 15 days

(A+B+C)’s 1 day work =

15

1

B alone can do a piece of work in = 30 days

B’s 1 day work =

30

1

C alone can do a piece of work in = 40 days

C’s 1 day work =

40

1

So,

A’s 1 day work =

15

1

−

30

1

+

40

1

=

15

1

−

120

4+3

=

15

1

−

120

7

=

120

8−7

=

120

1

∴ A can do a piece of work in 120 days