60 cm
30 cm
24 cm
-24 cm
The mirror formula is given as
1/v + 1/u = 1/f.. (i)
The position of object is 10cm left of mirror and position of image is 25 + 10 = 15cm right of mirror
u = -10cm and v = 15cm
substituting values in equation (i)
1/15 + 1/-10 = 1/f
1/f = -1/30
→ f = -30cm
The radius of curvature is given as
R = 2f = -60cm