Question

kindly solve it
ans is (c)
plzz plzz plzzzzzzzz solve it in a right way​

Answer 1

Answer:

Explanation:

1/f=1/f1+1/f2

1/f=-1/30+1/f2

1/f=1/v-1/u

here given magnification is 3

v/u = 3

v=3u

v=30cm

as real image is formed v= 30cm and u =-10

1/f2-1/30 = 40/300

30-f2=4f2

30 = 5f2

f2=6cm

as it has positive focal length it is convex

6cm convex