Here, `mu=1.5, R_(1)=-20cm,` and `R_(2)=+20cm`.
Substituting in equation, we get `f=-20cm`
Now, `u=+10cm , f=-20cm`
Substituting in eqution, we get
`(1)/(v)=(1)/(-20)+(1)/(10)` or `v=+20cm`
Thus, the rays now converge to a point 20cm in front of the lens.