Question

A convex lens produces an inverted image magnified three times of an

object at a distance of 15 cm from it. Calculate focal length of the lens​

Answer 1

Answer:

u=-15cm

m=v/u=-3(image is inverted)

v=3u=+45cm

now using the leans formula,

1/v-1/u=1/f

1/45-(1/-15)=1/f

1/45+1/15=1/f

f=45/4=+11.25cm