Question

(Compound interest formula)

A teenager is told that the colony of bacteria he observed in his tennis shoe doubles in size every 20 minutes. If the colony contained 15 bacteria when he first discovered them, write an equation that models the size of this colony of bacteria as a function of the number of hours, t, and calculate the amount of bacteria after 4 hours

Answer 1

amount = 15(2)^(t/20), where t is in minutes

so in 4 hours, or t = 240
amount = 15(2)^(240/20)
= 15(2^12) = ......