Question

An object placed 60 cm away from a lens a real is obtained 30 cm away from the lens.
what is the focal length ?​

Answer 1

Answer:

u = 60cm

v = 30 cm

f = ?

1/f = 1/v - 1/u

1/f = 1/30 - 1/60

1/f = 2-1/60

1/f = 1/60

f = 60 cm

Answer 2

Answer:

60cm is the correct answer