Question

A toy in the shape of a square pyramid has base edge 16 cm and slant height 10 cm. 500 of these are to be painted and the cost is 80 rupees per square meter. What would be the total cost?

Answer 1

Surface area = Curved surface area + base area

4 × 1/2 × 16 × 10 + 162 = 320 + 256 = 576cm

Total surface area of 500 square prism is = 500 × 576 = 28800 cm²

1 cm² = \(\frac{1}{10,000}\) m²

288000 cm² = \(\frac{288000}{10,000}\) = 28.8 m²

Cost of painting 1m² is = 80

Total cost = 28.8 x 80 = 2304 rupees