Question

an object is placed at a distance of 30cm in front of convex mirror of focal length 15cm.No need of diagram​

Answer 1

Given u=-30cm

f=15cm

1/v+1/u=1/f

1/v=1/15+1/30

2+1/30

3/30

v=10cm

Answer 2

f=15cm

u=-30cm

Using formula

1/f=1/v+1/u

or 1/15=1/v-1/30

or 1/v=1/15+1/30

or 1/v= (2+1)/30

or v=10cm.