Consider a jar formed by a cylinder and a hemispherical lid, both having the same radius 'r'. If the cylinder's height is also 'r', what is the ratio of the hemisphere's volume to the total volume of the jar?
Show answer & explanation
Correct answer: D
Explanation
Radius of cylinder = r, height = r
Radius of hemisphere = r
Volume of cylinder = πr²h
Volume of hemisphere = (2/3)πr³
Volume of cylinder = πr²(r) = πr³
Volume of hemisphere = (2/3)πr³
Total volume = πr³ + (2/3)πr³= (5/3)πr³
Ratio = (2/3)πr³ : (5/3)πr³= 2 : 5