A thin equiconvex lens is made of glass of refrative index 1.5 and its focal length is 0.2m. If it acts as a concove lens of 0.5m focal length when dipped in a liquid, the refractive index of liquid is

A thin equiconvex lens is made of glass of refrative index 1.5 and its

1.	A thin equiconvex lens is made of glass of refrative index 1.5 and its focal length is 0.2m. If it acts as a concove lens of 0.5m focal length when dipped in a liquid, the refractive index of liquid is
Answer» `17//8` `15//8` `13//8` `9//8` ANSWER :B