Kami, Karya and Kirti can together weave a carpet in 4 days. Kami by herself can weave the same sized carpet in 12 days and Kirti can do it in 10 days. How long will karya take to do the work by herself?

Explanation

Kami, karya and kirti can together weave a carpet in `4` days
In `1` days they weave
`(1/4)^(th)` part of carpet
Therefore Kami can weave the same carpet in `12` days
In `1` days she can weave
`1/12` part
kirti can weave the carpet in `10` days
In `1` days she can weave
`1/10` part
then, Karya can weave in `1` day
`1/4-(1/12+1/10)`
`1/4-1/12-1/10`
`(15-5-6)/60`
`4/(60)`
`1/15`
so,karya can weave the whole carpet in `15` days