Together Chotu and Nitu plough a field in 4 days. Nitu alone takes of 6 days to plough the same field. In how many days can Chotu alone plough the field ?

Explanation

Together chotu and Nitu plough a field in `4` days
In one day they plough
`1/4` part of field
Nitu alone plough the fieldin `6` days
In one day she plough
`1/6` part
Therefore nitu can plough in one day
`1/4` part - `1/6` part
`1/4-1/6`
`(3-2)/12`
`1/12` part
Therefore Nitu can plough thefield in
`12` days