Two thin lenses of power+2D and -1.5D are placed in contact .Find the a) power and b) focal length of the combination of lenses c) also state the nature of lens formed by the combination of these lenses. No links pls

Dear students,
Power of combination of lens is
P1 + P2=2D + (-1.5 D) = 0.5 D

As power is positive lens is convex lens of power 0.5 D
First Lens Power = +2.D
Focal length = 1m /P = 100 cm/2 = 50 cm
It is a convex lens
Ascend lens
Power = -1.5
focall length = 100 cm/1.5 = -67 cm
Itr is a concave lens with negative focal length.
Regards