2.16: Bacteria model with constants P and Q — parts (b), (c)

0606/22/O/N/20 — Question 10 · 4 marks · Exponentials, Population models

Continues Question 2.15 with the same model b=P+Qe2tb = P + Qe^{2t}.

Using b=P+Qe2tb = P + Qe^{2t} with Q=100e2115.7Q = \dfrac{100}{e^{2} - 1} \approx 15.7 and P=500Q484P = 500 - Q \approx 484 from part (a):
(b)
Find the number of bacteria present after 22 weeks.
[1]
(c)
Find the first week in which the number of bacteria is greater than 10000001\,000\,000.
[3]