Multiple choice

Find the radius of a sphere whose surface area is $154{cm}^{2}.$

  1. $3.5$ cm
  2. $4.5$ cm
  3. $4$ cm
  4. $3$ cm
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A Correct answer
Explanation

Surface area of sphere = 4*pi*r^2 = 154. 4 * (22/7) * r^2 = 154. r^2 = (154 * 7) / (4 * 22) = 7 * 7 / 4 = 49/4. r = 7/2 = 3.5.

AI explanation

The surface area of a sphere equals 4 times pi times the square of its radius, so 154 equals 4 multiplied by 22 over 7 and the radius squared. This simplifies to radius squared equals 154 times 7 divided by 88, which is 12.25. Taking the square root of 12.25 gives a radius of 3.5 centimeters.

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