If the distance between two images formed by upper and lower part of the lens of the point object placed at 30 cm from given lens is 11n (in cm) then find n:

Explanation

`(1)/(f_(L))=((3)/(2)-1)`
`((1)/(20)-(1)/(20))impliesf_(L)=20cm`
`(1)/(f)=(1)/(-10)-(2)/(20)=-(1)/(5)implies(1)/(v)+(1)/(-30)=(1)/(-5)`
`implies(1)/(v)=(1)/(30)-(1)/(5)`
for lens `(1)/(v)-(1)/(-30)=(1)/(20)`