The radius of a cylinder is increased by 120% and its height is decreased by 40%. What is the percentage increase in its volume?

Solution (By Examveda Team)

\[\begin{array}{*{20}{c}} {}&{{\text{Before}}}&{}&{{\text{After}}}&{} \\ {{\text{Radius}} \to }&5&:&{11}&{120\% \to \frac{{ + 6}}{5}} \\ {{\text{Height}} \to }&5&:&3&{40\% \to \frac{{ - 2}}{5}} \\ {{\text{Volume}} \to }&{{5^2} \times 5}&:&{{{11}^2} \times 3}&{} \end{array}\]
         
$$\% \,{\text{Increase}} \Rightarrow \frac{{238}}{{125}} \times 100 = 190.4\% $$