Mathematics for IGCSE & O level - Mensuration (Section 12 - No. 6)
What is the effect on the volume of a cone if both the radius and the height are doubled?
The volume is multiplied by 2.
The volume is multiplied by 4.
The volume is multiplied by 8.
The volume remains the same.
Giải thích
Volume of cone is (1/3)πr²h. If both r and h are doubled, the volume becomes (1/3)π(2r)²(2h) = 8 * (1/3)πr²h, which means the volume is multiplied by 8.