Question

a cylindrical pillar is 50 cm in diameter and 3.5 metre in height find the cost of painting the curved surface of the pillar at the rate of rupees 12.50 per metre square​

Answer 1

Answer:

r = 25 cm = 0.25 m

h= 3.5 m

C.S.A = 2π r h

= 2 ×22/ 7 ×0.25 × 3.5 = 5.5 m²

cost of painting the curved surface of the pillar = 5.5× 12.50 = Rs 68.75

Step-by-step explanation:

Answer 2

Answer :

➥ The Cost of painting a curved surface area = Rs.68.75

Given :

➤ Diameter of a cylindrical pillar = 50 cm

➤ Height of a cylindrical pillar = 3.5 m

➤ The cost of painting the curved surface of the pillar at the rate of rupees 12.50 per metre square

To Find :

➤ Cost of painting a curved surface area = ?

Required Solution :

To find the Cost of painting a curved surface area, at first we will find the radius of cylindrical pillar but our result in come in cm so we convert the radius of cylindrical pillar cm to m to convert cm to m divide the radius value by 100, after that we need to find the curved surface area of cylindrical pillar, after all this we will find Cost of painting a curved surface area$.$

For Finding Radius :

→ Radius = d/2

→ Radius = 50/2

→ Radius = 25 cm

Converting cm to m :

→ Radius = 25/100

→ Radius = 0.25 m

Now, we have Radius and it's height of a cylindrical pillar,

• Radius of a cylindrical pillar = 0.25 m
• Height of a cylindrical pillar = 3.5 m

And we need to find Curved surface area of cylindrical pillar.

We can find Curved surface area of cylindrical pillar by using the formula of Curved surface area of cylinder which says:

★ CSA = 2πrh ★

Here,

• CSA is the Curved surface area of cylinder in m².
• Value of π is 22/7
• r is the Radius of cylinder in m.
• h is the Height of cylinder in m.

So let's find Curved surface area (CSA) !

⇒ CSA = 2πrh

⇒ CSA = 2 × 22/7 × 0.25 × 3.5

⇒ CSA = 2 × 22 × 0.25 × 0.5

⇒ CSA = 44 × 0.25 × 0.5

⇒ CSA = 11 × 0.5

⇒ CSA = 5.5 m²

Now ,

We will find Cost of painting of a curved surface area.

⇛ Cost of painting = 5.5 × 12.50

⇛ Cost of painting = Rs.68.75

║Hence, the Cost of painting a curved surface area is Rs.68.75.║