r=212=10.5cm, SA=4πr2
=4×227×(10.5)2
=1386cm2
Cylindrical support,
r1 of circular end=1.5cm, h=7cm
Curved Surface Area =2πrh=2×227×1.5×7=66cm2
Area of circular end =πr2=227×(1.5)2=7.07 cm2
Area to be painted silver =8×(1386−7.07)cm2
=8×1378.9=11031.44cm2
Cost of silver color =Rs.0.25×11031.4
=Rs.2757.8
Area to be painted black =8×66=578cm2
Cost of painting black color=1528×0.05
=Rs.26.40
Total cost =Rs.2757.8+26.4
=Rs.2784.2