Question

9. A circular table top rests on three steel rods of radius
3 cm and height 28 cm. Find the curved surface area
of the steel rods and cost of painting them at the rate
of rupees 0.6 per sq. cm.(with correct solution and correct answer)​

Answer 1

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Given:

A circular table top rests on three steel rods of radius 3cm and height 28cm.

To find:

The curved surface area of the steel rods and cost of painting them at the rate of Rs.0.6/cm².

Explanation:

We have,

• Radius of three steel rods= 3cm
• Height of three steel rods=28cm

We know that formula of the curved surface area of cylinder: 2πrh

→ The curved surface area of 1 rod= $(2*\frac{22}{7} *3*28)cm^{2}$

→ The curved surface area of 1 rod= $(\frac{44}{\cancel{7} }*3*\:\cancel{28})cm^{2}$

→ The curved surface area of 1 rod= (44×3×4)cm²

→ The curved surface area of 1 rod= 528cm²

→ The curved surface area of 3 rod= (3×528)cm²

→ The curved surface area of three rod= 1584cm²

∴The cost of rod painting them Rs.0.6 per cm²;

⇒ The cost of all rod painting= Rs.(1584× 0.6)

⇒ The cost of all rod painting= Rs.950.4.

Answer 2

Answer:

The answer is ₹ 950.40

Hope it will help you