Q : 5    A cylindrical pillar is  \small 50\hspace{1mm}cm in diameter and 3.5\ m in height. Find the cost of painting the curved surface of the pillar at the rate of \small Rs \hspace{1mm} 12.50  per \small m^2

Answers (1)
H Harsh Kankaria


Radius of the cylindrical pillar, r = \frac{50}{2}\ cm= 25\ cm= 0.25\ m

Height of the cylinder, h  = 3.5\hspace{1mm}m

We know,

Curved surface area of a cylinder = 2\pi r h

\therefore Curved surface area of the pillar = 2\times\frac{22}{7}\times 0.25 \times3.5

= 1\times22\times 0.25\ m^2

= 5.5\ m^2


Cost of painting \small 1\ m^2 of the pillar =\small Rs \hspace{1mm} 12.50

\therefore Cost of painting the curved surface area of the pillar = \small Rs.\ (12.50\times5.5)

\small = Rs.\ 68.75

Therefore, the cost of painting curved surface area of the pillar is \small Rs.\ 68.75