Multiple choice

The radii of the top and bottom of a bucket of slant height $45$ cm are $28$ cm and $7$ cm respectively. The curved surface area of the bucket is

  1. $4950\ {cm}^{2}$
  2. $4951\ {cm}^{2}$
  3. $4952\ {cm}^{2}$
  4. $4953\ {cm}^{2}$
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A Correct answer
Explanation

Curved surface area of a frustum = pi * (R + r) * l. R = 28, r = 7, l = 45. CSA = (22/7) * (28 + 7) * 45 = (22/7) * 35 * 45 = 22 * 5 * 45 = 110 * 45 = 4950 cm^2.

AI explanation

A bucket is in the shape of a frustum of a cone, and its curved surface area is found by the formula π times the sum of the radii times the slant height (π(R + r)l). Substituting the given values gives π times (28 plus 7) times 45. Calculating this results in 22 divided by 7 times 35 times 45, which equals 22 times 5 times 45. Multiplying these gives 110 times 45, resulting in a curved surface area of 4950 square cm.

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