Question

The following equation models the exponential decay of a population of 1,000 bacteria. About how many days will it take for the bacteria to decay to a population of 120?

1000e^ -.05t

A. 2.5 days
B. 4.2 days
C. 42.4 days
D. 88.5 days

Answer 1

Explanation:

120 = 1000 e^(-.05t)

120/1000 = e^(-.05t) take natural LN of both sides

-2.12 = - .05t

t = 42.4 days