Question

If the radius of a sphere is doubled, then its volume is increase by __________.

• A. $100\%$
• B. $200\%$
• C. $700\%$
• D. $800\%$

Answer 1

The correct option is C $700\%$

Given that radius of the sphere is doubled.

Let the Initial volume of sphere $V=\frac{4}{3}\pi r^3$

Incresed volume $V^{\prime }=\frac{4}{3}\pi (2r{)}^3=8V$

Thus, Volume is increased by:

$\frac{8V-V}{V}\times 100=700\%$