Volumes of solids of revolution:

Volume = 750 u^3

Distance between the two points = x and x+30 (they need to be 30 cm's apart)

Formula:$\displaystyle

V = \pi \int (75/x)^2 dx

$

I have to find that x =15.5 and x+30 = 45.5.

PS: there is slight error in the volume, it may be a little more, or less.

Any help?