A certain person has a minimum distance of distinct vision of 150cm. He wishes to read at a distance of 25cm. What focal length glasses should he use?

A certain person has a minimum distance of distinct vision of 150cm. H

1.	A certain person has a minimum distance of distinct vision of 150cm. He wishes to read at a distance of 25cm. What focal length glasses should he use?
Answer» `+40CM` `+30CM` `-30cm` `-40cm` ANSWER :B