Dean is running to raise awareness and money for cancer. He finds 2 people who have pledged to donate money based on the distance he runs. His neighbor says he will donate $0.25 for every 40 feet Dean runs. His aunt also says that she will donate $24 for every mile he runs. If Dean runs a total of 3 miles during the cancer awareness run, how much money will he have raised based on these two donations?

For every corresponding pair of cross sections, the area of the cross section of a sphere with radius r is equal to the area of the cross section of a cylinder with radius and height 2r minus the volume of two cones, each with a radius and height of r. a cross section of the sphere is and a cross section of the cylinder minus the cones, taken parallel to the base of cylinder, is the volume of the cylinder with radius r and height 2r is and the volume of each cone with radius r and height r is 1/3 pie r^3. so the volume of the cylinder minus the two cones is therefore, the volume of the cylinder is 4/3pie r^3 by cavalieri's principle. (fill in options are: r/2- r- 2r- an annulus- a circle -1/3pier^3- 2/3pier^3- 4/3pier^3- 5/3pier^3- 2pier^3- 4pier^3)