# In how many days can the do it work:

A and B can do a piece of work in 18 days; B and C in 24 days, C and A in 36 days. In how many days can they do it all working together :

- 12
- 13
- 16
- 26

**Answer: (3) 16 **

**Explanation:-**

A and B can do a piece of work = 18 days

Therefore, A and B can do a work in a day = 1/18

B and C can do a piece of work = 24 days

Therefore, B and C can a work in a day = 1/24

A and A can do a piece of work = 36

Therefore, C and A can a work in a day = 1/36

So, A, B and C all working together in a day = (1/18 + 1/24 + 1/36)/2

= (4 + 3 + 2)/72 x 2

= 9/72 x 2

= 1/16

Thus, 16 days can they do it all working together.

Hence, the correct answer is option (3) 16.