Let's consider the following diagram-

The relation between the object distance, the image distance and the radius of curvature of the spherical surface can be written as
vμ2−uμ1=Rμ2−μ1...(1)
Substitute the values of the known parameters into equation (1) and solve to calculate the required image distance.
v1.5−−151=⇒=⇒301.5−1.0v1.5=601−151−201v=−30
Hence, the image is formed at a distance of 30cm from the pole on the same direction as the object is placed.