A bacteria population starts at 2,032 and decreases at about 15% per day. After how many days will there be 321 bacteria?

A. About 1.1 days
B. About 0.2 days
C. About 11.4 days
D. About 13.2 days

Question

A bacteria population starts at 2,032 and decreases at about 15% per day. After how many days will there be 321 bacteria?

A. About 1.1 days
B. About 0.2 days
C. About 11.4 days
D. About 13.2 days

kropot72 · Answer

The population change with time can be modeled by this equation:
$$\large P _{t}=P _{0}(0.85)^{t}$$
where Pt=321 and P0 = 2032
Now you need to plug these values into the equation, and then solve to find the value of t.