Question 55148
You know the formula for the volume of a cylinder {{{V = r^2h}}} You're given the radius and volume and you have to solve for the height. 

So basically, 
{{{V = r^2h}}}
{{{V=250}}}
{{{r = 5}}}

Pluging it in:
{{{250 = (5)^2h}}}

You can solve for h from there.