# days taken for a piece of work

Teacher's questions

### days taken for a piece of work

A,B & C together can finish a piece of work in 4 days. A alone can do in 12 days & B alone in 18 days. How many days will taken by C to do it alone?

Pls explain how do i workout this sum?
rameshppc

Posts: 10
Joined: Sat Aug 18, 2018 9:37 am
Reputation: 0

### Re: days taken for a piece of work

Let C finish work in x days $$\Rightarrow for 1 day C finish$$ $$\frac{1}{x}$$of work; A finish for 1 day $$\frac{1}{12}$$; B- for 1 day finish $$\frac{1}{18}$$
$$\Rightarrow \frac{4}{12} + \frac{4}{18}+\frac{4}{x} = 1 \Leftrightarrow 3x+2x+36=9x\Leftrightarrow x=9$$ days.

nathi123

Posts: 22
Joined: Sun Sep 17, 2017 1:56 pm
Reputation: 20

### Re: days taken for a piece of work

wow thanks a lot...
You are really great..

rameshppc

Posts: 10
Joined: Sat Aug 18, 2018 9:37 am
Reputation: 0