Question

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

• A. 10%
• B. 20%
• C. 11%
• D. 21%

Answer 1

Answer:

D. 21%

$V=\pi r^2h$

$r=10$

$V=100\pi h$

$r_1=11$

$V=\pi 11^2h=121\pi h$

change in volume /original volume x 100

$=\frac{21\pi h }{100\pi h }\times 100$

=21%