Question

4. A concave lens has focal length of 15 cm. At what distance should the object from

the lens be placed so that it forms an image at 10 cm from the lens?

A. +30cm

B. -30mm

C. -30cm

D. +30mm​

Answer 1

Answer:

-30 is the correct answer

Answer 2

Answer:

c) _30 cm

Explanation:

1/u is equal to1/v -1/f

-1/10+1/15 is equal to _1/30cm

so answer is -30cm