Height (h) of the cylindrical pillar = 3.5 m
Radius (r) of the circular end of the pillar 502=25 cm
CSA of pillar =2πrh
=(2×227×0.25×3.5)m2=(44×0.125)m2=5.5 m2
Cost to paint 1m2 area = Rs. 12.50
Cost to paint 5.5 m2 area=Rs.(5.5×12.50)
= Rs. 68.75
Therefore, the cost of painting the CSA of the pillar is Rs. 68.75.