Multiple choice

What will be the amount paid by an Eskimo to get a hemispherical igloo made with a sheet of canvas if the radius of the igloo's base is 7 m and the cost of canvas is Rs. 25/sq.m?

  1. Rs. 8000

  2. Rs. 7700

  3. Rs. 7000

  4. Rs. 5500

  5. None of these
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The surface area of a hemisphere (excluding the base) is 2 * pi * r^2. With r = 7 and pi = 22/7, SA = 2 * (22/7) * 49 = 308 sq.m. Cost = 308 * 25 = 7700.

AI explanation

The canvas covers the curved surface area of the hemisphere, calculated using the formula 2πr². Substituting the radius gives 2 × (22/7) × 7² = 308 square meters. Multiplying this area by the canvas cost of Rs. 25 per square meter gives a total amount of 308 × 25 = Rs. 7700.

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