A far sighted person cannot focus distinctly on objects closer than Im. What is the power of lens that will permit him to read from a distance of 40cm?

A far sighted person cannot focus distinctly on objects closer than Im

1.	A far sighted person cannot focus distinctly on objects closer than Im. What is the power of lens that will permit him to read from a distance of 40cm?
Answer» Solution :As NEARPOINT is 1M and distance of OBJECT is 0.40m both in front of LENS. `P=1/f=1/v+1/u=1/-1 -1/-0.40 IMPLIES P=1.5D`