SURFACE2. The front compound wall of a house isdecorated by wooden spheres of diameter 21cm, placed on small supports as shown in Fig13.32. Eight such spheres are used for thispurpose, and are to be painted silver. Eachsupport is a cylinder of radius 1.5 cm and height LIITE7 cm and is to be painted black. Find the costof paint required if silver paint costs 25 paiseper cm2 and black paint costs 5 paise per cm 2Fig. 13.32d by 25% By what per cent does its curv

SURFACE2. The front compound wall of a house isdecorated by wooden sph

1.	SURFACE2. The front compound wall of a house isdecorated by wooden spheres of diameter 21cm, placed on small supports as shown in Fig13.32. Eight such spheres are used for thispurpose, and are to be painted silver. Eachsupport is a cylinder of radius 1.5 cm and height LIITE7 cm and is to be painted black. Find the costof paint required if silver paint costs 25 paiseper cm2 and black paint costs 5 paise per cm 2Fig. 13.32d by 25% By what per cent does its curv
Answer» Radius of wooden sphere = 10.5 cmSA of wooden sphere = 1386 cm²radius of cylindrical support = 1.5height = 7 cmso, CSA = 66 cm²and area of circular end of cylindrical support = 7.07 cm²area to be painted silver = 8 * (1386 - 7.07) = 11031.44 cm²cost of painting with silver = 11031.44 * 0.25 = RS.2757.86painting black = 528 * 0.05 =RS 26.40total cost = 2757.86 + 26.40 = RS. 2784.26