Correct Answer - B
`(1)/(F)=(1)/(f_l)+(1)/(f_m)+(1)/(f_l)`
`(2)/(f_l)+(1)/(f_m)=(2)/(20)+(1)/((22)/(2))=(1)/(10)+(1)/(11)`
`=(21)/(110)`
The silvered lens behaves as concave mirror of focal length `(110)/(21)cm`
`(1)/(v)+(1)/(u)=(1)/(f)`
`(1)/(v)+(1)/(-10)=(1)/((-110)/(21))`
`(1)/(v)=(1)/(10)-(21)/(110)=(11-21)/(110)=-(1)/(11)`
`v=-11cm`, real image