Annoying Math 2c question (please help!)

<p>If the height of a right circular cone is decreased by 8 percent by what percent must the radius of the base be decreased so that the volume of the cone is decreased by 15 percent?</p>

<p>Ans 4%</p>

<p>please help my test is tmr and i don't understand this...</p>

<p>The Volume formula for a right circular cone is V=1/3<em>Pi</em>r^2<em>h.
You can express the new volume as 0.85V=1/3</em>Pi<em>R^2</em>0.92h.
Divide the two equations:
Hence, the radius must decrease by 4%. </p>

<p>Good luck on your test!</p>