The radius and height of a solid cylinder is increased by 20% and 16…

                  Old      :      New

radius:         5       :        6

height :        6       :        7     

Volume:       5²×6    :      6²×7

                  25      :         42         (*Inc. by 17)

Increase % = \(\frac{17}{25}\)×100 = 68%

OR

Volume of cylinder = \(\pi \)r²h .... (i)

New volume =  \(\pi \) (\(\frac{6}{5}\)r)² × (\(\frac{7}{6}\)h) = \(\frac{42}{25}\) \(\pi \)r²h

= 68% increase