Appeared in: 2026 (3 sets)
(iii) If the distance between object and screen is $80.00\text{ cm}$ and the lens forms sharp images at two positions separated by $20.00\text{ cm}$., the focal length of convex lens is
(A) $15.50\text{ cm}$
(B) $18.75\text{ cm}$
(C) $20.50\text{ cm}$
(D) $22.75\text{ cm}$