Question

A cylindrical pillar is 50 cm in diameter and 3.5 m in height. Find the cost of painting the curved surface of the pillar at the rate of ₹ 12.50 per $m^2.[Assume\pi =\frac{22}{7}]$

• A. ₹ 78.75
• B. ₹ 68.75
• C. ₹ 98.75
• D. ₹ 48.75

Answer 1

The correct option is B

₹ 68.75

Height of the cylindrical pillar, h = 3.5 m
Radius of the circular end of the pillar, r
$=\frac{50}{2}=25cm=0.25m$
CSA of pillar $=2\pi rh$
$=(2\times \frac{22}{7}\times 0.25\times 3.5)m^2=(44\times 0.125)m^2=5.5m^2$
Cost to paint $1m^2$ area = ₹ 12.50
Cost to paint $5.5m^{2}area=₹(5.5\times 12.50)=₹68.75$
Therefore, the cost of painting the curved surfaceof the pillar is ₹ 68.75.