Q.If the radius of the base of a right circular cone is halved and its height is doubled, the volume of the cone remains the same.

The statement is false.
If the original radius is \(r\), then the new radius becomes \(\cfrac{r}{2}\), and if the original height is \(h\), then the new height becomes \(2h\). ∴ Original volume = \(\cfrac{1}{3} πr^2 h\) cubic units New volume = \[ = \cfrac{1}{3} π\left(\cfrac{r}{2}\right)^2 × 2h = \cfrac{1}{3} π \cfrac{r^2}{4} × 2h = \cfrac{1}{6} πr^2 h \] Which is not equal to the original volume.
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