16Hit1600
Advanced MathVery hardExponential growth between two readings

Advanced Math practice question

A bacteria population is 5 million at noon and 40 million at 3 p.m., and it grows exponentially. In millions, what was the population at 1 p.m.?

Answer: 10

Over 3 hours the population multiplied by 8 = 2³, so it doubles each hour: 5 → 10 at 1 p.m.

Common wrong answers

If you answered 15
15 adds 10 to 5, a linear step.
If you answered 20
20 is the population at 2 p.m.
If you answered 16.67
16.67 assumes linear growth (5 + 35/3).

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