Pls solve the following: (Related Rates)

1. A man 6 feet tall walks at a rate of 5 fteet per second away from alight that is 15 feet above the ground. (a) When he is 10 feet from the base of the light, at what rate is the tip of his shadow moving? (b) when he is 10 feet from the base of the light, at what rate is the length of his shadow changing?

2. A spherical balloon is being inflated at the rate of 5 cubic meters per minute. At what rate is the radius increasing when the radius is 5 m?

3. Water is flowing into a cylindrical tank of radius 4 ft at the rate of 9 cubic feet per minute. How fast is the water level rising?