Radius of curvature(r)=12cm focal length(F) = r \div 2 → 12 \div 2 = 6cm therefore F = 6cm magnification(M) = v \div u 1.5 = v \div u :v = 1.5u Using mirror formula 1/f =1/v + 1/u \(\frac{1}{6}\) =\(\frac{1}{1.5u}\) + \(\frac{1}{u}\) \(\frac{1}{6}\) = \(\frac{1 + 1.5}{1.5u}\) \(\frac{1}{6}\) = \(\frac{2.5}{1.5u}\) 1 * 1.5u = 2.5 * 6 u = \(\frac{15}{1.5}\) = 10 therefore object distance =10cm.