Question

A cylindrical pillar is 100 cm in diameter and 2.5 m in height.Find the cost of painting curved surface of the pillar at the rate of rs 16 per m2​

Answer 1

Answer:

126 Rs.

Step-by-step explanation:

diameter = d= 100cm= 1m

radius =r = d/2= 1/2= 0.5m

h= 2.5 m

formula CSA= 2pi r h= 2× pi× 0.5× 2.5

= 7.854 m^2

Cost of painting per m^2 at Rs. 16 = 16× CSA = 16× 7.854

= 125.66 Rs.

Or approximately 126 Rs.

Answer 2

Answer:

Given that :-

• Height of the cylinder pillar = 2.5m
• Radius of the cylinder pillar = 100/2 = 50cm

Converting to m = 50/100 = 0.50m

So,

Curved surface area = (2πrh)

=> 2 × 22/7 × 0.50 × 2.5

=> 2 × 22/7 × 1.25

=> 7.85cm²

Then,

• Cost of painting curved surface of pillar for per m² = Rs.16

»» Cost of painting 7.85m² :-

=> 7.85 × 16

=> Rs. 125.6

Therefore, Cost of painting the cuverd surface area of the pillar is Rs. 126 (approx.)