A hemispherical bowl made of iron has an inner diameter of 84 cm. Find the cost of tin plating it on the inside at the rate of 21rs per 100 cm2 (take π = 22/7) correct to two places of decimal.
Show answer & explanation
Correct answer: A
Explanation
The correct answer is option 1 i.e. ₹2,328.48.
Formula used:
Curved surface area of hemisphere = 2πr2
Calculations:
Inner Diameter = 84 cm
Inner Radius = 84/2 cm = 42 cm
Using the above equation;
⇒ Curved surface area of the hemisphere = 2 × 22/7 × 422
⇒ 2 × 22 × 6 × 42 = 11088 cm2
The cost of tin-plating 100 cm2 of the bowl = Rs. 21
The cost of tin-plating 11088 cm2 area of the bowl = (21/100) × 11088
= Rs. 2,328.48
Hence, the cost of tin-plating is Rs. 2328.48