Question

10 cylindrical pillars of a building have to be painted. If the diameter of each pillar is 50 cm and
the height is 4 m, what will be the cost of painting @ 14 per m²??​

Answer 1

Given :-

• 10 cylindrical pillars of a building have to be painted. If the diameter of each pillar is 50 cm and the height is 4 m

To find :-

• What will be the cost of painting @ 14 per m²

Solution :-

• Diameter of cylindrical pillars = 50cm

• Radius of cylindrical pillars = 50/2 = 25cm = 25/100 = 0.25m

• Height of cylindrical pillars = 4 m

Now, curved surface area of cylindrical pillars

→ 2πrh

• Where " r " is radius and " h " is height.

→ 2 × 22/7 × 0.25 × 4

→ 44/7 × 1

→ 44/7 m²

Area of 10 cylindrical pillars

• 10 × 44/7 = 440/7 m²

The cost of painting @ 14 per m²

→ Total cost

→ 440/7 × 14

→ 440 × 2

→ Rs.880

Hence,

• Total cost for painting 10 cylindrical pillars is Rs.880

Answer 2

Step-by-step explanation:

Given :

• No. of pillars = 10

• Diameter of each pillar = 50 cm

• the height = 4 m,

To Find :

• what will be the cost of painting @ 14 per m²??

Solution :

Radius of each pillar = 50/2 cm

= 25 cm

= 25/100 m

= 1/4 m

Curved Surface Area of Cylinder = 2πrh

Substitute all values :

= 2 × 22/7 × 1/4 × 4

= 44/7 × 4/4

= 44/ 7

Total cost = 44/7 × 14 × 10

= 44 × 2 × 10

= 880

Answer: Total cost is ₹880.