Cylinder twice

If the radius of the cylinder increases twice, and the height is reduced twice, then the volume of the cylinder increases (how many times?):

Correct answer:

n =  2

Step-by-step explanation:

$$\begin{gathered} V=\pi r{}^{2}h \\ {V}_2=\pi (2r{)}^2(h/2)=2\pi r^{2}h=2V \\ n=V_2/V \\ n=2 \end{gathered}$$

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