Given that
Distance of the object placed from a concave mirror u = -32 cm
ho = 1cm
As the image is inverted, the magnification must be negative
hi = -1.5
hi/ho = -v/u
-1.5/1 = -v/(-32)
v = -48 cm
Image is 48 cm from the pole and on the same side of the object
Mirror formula 1/f = 1/u + 1/v
1/f = -1/32 – 1/48
f = -19.2 cm
The focal length of the mirror is 19.2 cm