Multiple choice

The surface area of a football is $\displaystyle 616{ mm }^{ 2 }$. Calculate its radius.

  1. $4$ mm
  2. $7$ mm
  3. $6$ mm
  4. $5$ mm
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Surface area of a sphere = 4*pi*r^2 = 616. 4 * (22/7) * r^2 = 616. r^2 = 616 * 7 / 88 = 49. r = 7 mm.

AI explanation

The surface area of a sphere is given by the formula A = 4 * pi * r^2. Setting the area to 616 mm^2 gives 616 = 4 * (22/7) * r^2. Simplifying this yields r^2 = 616 * 7 / 88, which results in r^2 = 49. Taking the square root gives the radius as 7 mm.

Keep practicing — related questions