To calculate the cost of polishing of circular table, we have to calculate its area first of all
.Here, Given diameter of the circular table-top = 1.6 m.
Hence, r = 0.8 m
Area = π r^2
= 3.14 × 0.8 × 0.8 = 2.0096 sq m
Cost of polishing = Rate × Area
= Rs 15 × 2.0096 = Rs 30.144