If the base radius of a cylinder is increased by 10% and the height remains unchanged, then find the percentage increase in the volume of the cylinder.

21%

Volume of cylinder = πr²h

10% = \(\frac{1}{10}\)

                           Old              New

Radius                  10      :        11

Radius                  10      :        11

Height                   1       :         1

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Volume =         100        :        121

Percentage increase in volume of cylinder = \(\frac{121 - 100}{100}\) × 100%

= \(\frac{21}{100}\) × 100% 

= 21%