.
3 hours = 180 minutes = 4.5 40-minutes doubling periods.
So, after 3 hours, the number of EColi will be
= 678.82 = 679 (rounded). ANSWER
Solved.
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To see many other similar and different solved problems on bacteria growth, look into the lesson
- Bacteria growth problems
in this site.
Also, you have this free of charge online textbook in ALGEBRA-I in this site
- ALGEBRA-I - YOUR ONLINE TEXTBOOK.
The referred lesson is the part of this online textbook under the topic "Logarithms".
Save the link to this online textbook together with its description
Free of charge online textbook in ALGEBRA-I
https://www.algebra.com/algebra/homework/quadratic/lessons/ALGEBRA-I-YOUR-ONLINE-TEXTBOOK.lesson
to your archive and use it when it is needed.