Multiple choice

What is the total cost of painting a cone at the rate of Rs.60 per square metre? Statement I: The radius and the slant height of the flask are 21 m and 16 m respectively Statement II: The area of the base of cone is 616 sq. m and its height is 14 m.

  1. If the data in statement I alone is sufficient to answer the question.

  2. If the data in statement II alone is sufficient to answer the question.

  3. If the data either in statement I alone or statement II alone are sufficient to answer the question.

  4. If the data given in both I and II together are not sufficient to answer the question.

  5. If the data in both the statements I and II together are necessary to answer the question.
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

To find the painting cost, we need the total surface area of the cone. Statement I gives radius 21 m and slant height 16 m, so curved surface area = pi × 21 × 16 = 336pi sq.m, and cost = 336pi × 60 = Rs. 20,160pi. Statement II gives base area 616 sq.m, so radius = sqrt(616/pi) = 14 m, and height 14 m, giving slant height = sqrt(14² + 14²) = 14√2 m. Then curved surface area = pi × 14 × 14√2 = 196pi√2 sq.m, and cost can be calculated. Each statement alone provides sufficient data to determine the cost.

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