questions I am having trouble with

14. When an object is dropped from rest it falls about 5 m in the first second, 15 m in the second, second, 25 m in the third second, and so on. If a rock is dropped from a hot air balloon and takes 16 seconds to hit the ground, how high above the ground is the balloon? 14) 15. Determine the sum of all the multiples of 4 between 1 and 999.A hard rubber ball is dropped from a moving van with a height of 5 metres. The ball rises to 80% of the previous height after each bounce. a) determine the total vertical distance the ball has traveled when it strikes the ground the eighth time.b) estimate the total vertical distance the ball travels before it comes to rest.For what values of x for the geometric series have a sum to infinity? 1 + 3x + 9x3+ 27x +