about algebra 2?

Question

suppose the intial height from which a rubber ball drops is 100in. The rebound heights to the bearest inch are 80,64,51,41.......
a) what is the rebound ratio for this ball?
b) what is the height of the tenth rebound?
c) after how many bounces will the ball rebound less than 1in ?less than 0.1 in?

Answer 1

a) 80/100, 64/80, 51/64 always 0.80 or 80%
b) [0.8^10]*100 (0.8*0.8*0.8... 10 times*100)
c) 1= 0.8^n*100 solve for closest n, take n+1 if nec.
0.1= ... same trick.