Multiple choice

A tent is of the shape of a right circular cylinder up to a height of 3 metres and then becomes a right circular cone with maximum height of 13.5 metres above the ground. If the radius of the base is 14 metres, the cost of painting the inner side of the tent at the rate of Rs. 2 per square metre is-

  1. Rs. 2050

  2. Rs. 2060

  3. Rs. 2068

  4. Rs. 2080
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Total surface area to paint = CSA of cylinder + CSA of cone. Cylinder: 2πrh = 2 × π × 14 × 3 = 84π. For the cone, slant height l = √(h² + r²) = √(10.5² + 14²) = √306.25 = 17.5m. CSA = πrl = π × 14 × 17.5 = 245π. Total area = 329π ≈ 1034 m². Cost = 1034 × 2 = Rs. 2068.

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