Which quantity is best modeled by a linear function

Abouncy ball is dropped such that the height of its first bounce is 5.5 feet and each successive bounce is 64% of the previous bounce's height. what would be the height of the 7th bounce of the ball? round to the nearest tenth (if necessary).

Adice is rolled 5 times. how many possible rolls are there? ( determine the number of outcomes using only the fundamental counting principal )

We just started the introduction into circles and i have no idea how to do this.