Problema Solution

A cylinder has a radius of r and a height of h. A rectangular box has a length of r, a width of h and a height of h. Their combined volume is V=pir^2h + h^2r

If their combined volume is 600 cubic inches and h is 5 inches, solve for the radius (r).

Answer provided by our tutors

sol.

       as given in the question the combined volume of both the cylinder and cuboid is

                           V = pi*r^2*h + h^2*r

   now given V = 600

            => hr(pir + h) = 600

           => r (pir + 5) = 120

           => pir^2 + 5r - 120 =0

           => r = 5.43 inches or -7.02 (not possible)

  hence, radius of the cylinder is 5.43 inches