At 10am a colony of bacteria begins with 3000 microorganisms. At 4pm, there are 3600 microorganisms. How many are there at 7:30pm?

Answer 1

P(t) = 3000e^rt, where t is time in hours from 10am. At 4pm t = 6 hours. vso, 3600 = 3000e^6r; r = ln(6/5)6 =

= 0.030387; P(t) = 3000e^0.030387t.

At 7:30pm t = 9.5 hours P(9.5) = 3000e^{0.030387· 9.5} = 4004 bacteria

Answer 2

(3600 - 3000)/6 = 100 per hour. 3.5 hours later, 100 * 3.5 = 350 more. So total is 3600 + 350 = 3950