Acylinder shaped container has a radius of 30 cm and a height of 100 cm. a glass sphere with a radius of 12 cm is placed inside the cylinder shaped container and then the container is completely filled with water.

what is the approximate volume of water contained in the cylinder?

use 3.14 as an approximation for pi.

Your volume formula is not correct.

anyway volume = 1/3 * h * r^2*pi, this liquid volume is constant regardless of the container.
so plug in h and r, v = 1/3 * 6 * 3^2 *pi= 18pi

cylinder is just area of circle * h, so
pi*r^2*h = 18 pi
r^2*h= 18
3*3*h=18
h = 2

basically set the volume equal to each other, and plug in r, and solve for H in cylinder eqn