Multiple choice

A metallic sphere of radius 9 cm is melted and recast into a cylinder, whose height is 12 cm. What is the radius of the cylinder?

  1. 9 cm

  2. 18 cm

  3. 21 cm

  4. 15 cm

  5. None of these

Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

As volume of the cylinder is equal to the volume of the sphere,

πr2 × 12 = 4/3π93

r2 x 12 = (4 x 9 x 9 x 9)/3

r = 9 cm