days taken for a piece of work

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days taken for a piece of work

Postby rameshppc » Mon Aug 27, 2018 9:59 am

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?
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Re: days taken for a piece of work

Postby nathi123 » Mon Aug 27, 2018 12:32 pm

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

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Re: days taken for a piece of work

Postby rameshppc » Thu Aug 30, 2018 10:41 am

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

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