Question

An eye specialist prescribes spectacles having combination of convex lens of focal length 40cm in contact with a concave lens of focal length 25cm

Answer 1

here is your answer OK ☺☺☺☺☺☺☺


- 100/40 + 100/25

-5/2+4

-5+8/2

= 3/2

=1.5d

1.5 d will be the total power

hope this helps u