Two transparent media having refractive indices \( 1.0 \) and \( 1.5 \) are separated by a spherical refracting surface of radius of curvature \( 30 \, \text{cm} \). The centre of curvature of surface is towards denser medium and a point object is placed on the principle axis in rarer medium at a distance of \( 15 \, \text{cm} \) from the pole of the surface. The distance of image from the pole of the surface is ______ \( \text{cm} \).
