If the power of a lens is +5 diopter, what is its focal length?

If the power of a lens is

+ 5 diopter

, the focal length is

20 cm

.
Given,
Power,

P = + 5 D

and we know that,
Power,

P = \frac{1}{f}

,where

f

is the focal length of the lens. By putting the values in the above formula, we get

f = \frac{1}{+ 5}

f = 0.2 m

f = 0.2 \times 100 cm

f = 20 cm .

If the power of a lens is $+ 5 diopter$ , what is its focal length?