Which of the following word problems represent an exponential function? (choose all that apply)

Your

a)Renting a canoe costs $10 per day and an additional $1 per hour

b)Bacteria grow at a rate 2.5 every 6 hours.

c)Your savings has a growth rate of 4% compounded quarterly over the next 10 years.

d)How long will it take a ball to land on the ground if it is thrown at an upward velocity of 24 ft/sec from a height of 5 feet?