Question

A mansion has 12 right cylindrical pillars each having radius 50 cm and height 3-5 m. Find the cost to . paint the curved surface of pillars at $ 20 per square meter. 2. = 50cm​

Answer 1

Answer:

Given : Radius of cylindrical pillar = r = 50 cm = 0.5 m

Height of cylindrical pillar = h = 3.5 m

Number of cylindrical pillars = 12

Cost of painting per square metre = Rs 20

To find : The cost of painting the lateral surface of the pillars

Formula : CSA of cylinder = 2πrh

Solution : The lateral surface of a cylinder is the curved surface of the cylinder.

Area to be painted for one pillar = CSA of cylinder = 2πrh

= 2 ×

× 0.5 × 3.5

= 11 m2

Total area to be painted for 12 cylinders = 11 × 12 = 132 m2

Total cost of painting = Area to be painted × cost of painting per square meter

= 132 × 20 = Rs 2640

∴ The cost of painting 12 cylindrical pillars is Rs 2640.