Multiple choice

If the total surface area of a solid hemisphere is $462$ $\displaystyle { cm }^{ 2 }$, find its volume. Note: Take $\displaystyle \pi =\frac { 22 }{ 7 } $

  1. $716$
  2. $718.67$
  3. $720.87$
  4. $840$
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Total surface area of a hemisphere = 3 * pi * r^2 = 462. So, 3 * (22/7) * r^2 = 462, which gives r^2 = 49, so r = 7. Volume = (2/3) * pi * r^3 = (2/3) * (22/7) * 343 = 15026.66 / 21 = 718.666...

AI explanation

Using the total surface area formula for a solid hemisphere, 3 * pi * r^2 = 462, we find the radius by calculating r^2 = 462 * 7 / 66, which gives r = 7 cm. The volume of a solid hemisphere is (2/3) * pi * r^3, so substituting the values gives (2/3) * (22/7) * 7^3 = 718.67 cm^3.