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Radius of sphere, r = (21/2) = 10.5 cm Recall that the surface area of sphere = 4πr 2 sq units = 4 × (22/7) × (10.5)2 = (88/7) × 110.25 = 1386 sq cm Given radius of the circular end of cylindrical support, r1= 1.5 cm Height of cylindrical support, h = 7 cm CSA of cylindrical support = 2πrh sq units = 2 × (22/7) × (1.5) ´ 7 = 44 × 1.5 = 66 sq cm Area of the circular end of cylindrical support = πr2 = (22/7) × (1.5)2 = (22/7) × 2.25 = 7.07 sq cm Area to be painted with silver colour = [8(1386 − 7.07)] sq cm = (8 × 1378.93) sq cm = 11031.44 sq cm Cost for painting with silver colour = Rs (11031.44 × 0.25) = Rs 2757.86 Area to be painted with black colour = (8 × 66) sq cm = 528 sq cm Cost of painting with black colour = Rs (528 × 0.05) = Rs 26.40 Total cost for painting = Rs 2757.86 + Rs 26.40 = Rs 2784.26 Therefore, total cost of painting as desired is Rs 2784.26