Question

The radius of base and the height of a right circular cylinder are each increased by 20%. The volume of the cylinder will increase by

• A. 72.8%
• B. 96%
• C. 40%
• D. 60%

Answer 1

The correct option is A 72.8%

$V_2/V_1=\frac{\pi {\left(\frac{6}{5}r\right)}^2\left(\frac{6}{5}h\right)}{\pi r^{2}h}$$=\frac{216}{125}=1.728$
Thus 72.8% increase in volume