Multiple choice

Find the radius of the biggest ball that can fit inside a 5 cm tall cylinder with a volume of 45 cubic cm.

  1. $\dfrac{3}{\sqrt \pi}$ cm
  2. $\dfrac{4}{\pi}$ cm
  3. $\dfrac{5}{\pi}$ cm
  4. $\dfrac{6}{\pi}$ cm
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Volume of cylinder = pi * r^2 * h = 45. Given h = 5, pi * r^2 * 5 = 45 => r^2 = 9/pi => r = 3/sqrt(pi).

AI explanation

Using the volume of a cylinder formula, V = pi * r^2 * h, we can substitute the known values: 45 = pi * r^2 * 5. Solving for the radius gives r^2 = 9 / pi, so r = 3 / sqrt(pi) cm. The radius of the largest ball that can fit inside is constrained by this cylinder radius, making it 3 / sqrt(pi) cm.

Keep practicing — related questions