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31 votes
31 votes
In a lab experiment, 100 bacteria are placed in a petri dish. The conditions are such

that the number of bacteria is able to double every 13 hours. How long would it be, to
the nearest tenth of an hour, until there are 156 bacteria present?

User Vadym Vasyliev
by
2.7k points

2 Answers

21 votes
21 votes

Answer: 8.3

Explanation:

User Cachonfinga
by
2.9k points
19 votes
19 votes

Answer: 8.34 hr

Explanation:

Given

Initially, 100 bacteria are placed in a Petri dish

bacteria doubles in every 13 hours

So, a function that defines this relation is given as


\Rightarrow B=B_o(2)^(t)/(13)

where,
B=\text{No of bacteria at any time}


B_o=\text{Intial bacterias}\\t=\text{time in hrs}

for
B=156


\Rightarrow 156=100* 2^{(t)/(13)}\\\\\Rightarrow 1.56=2^{(t)/(13)}\\\\\Rightarrow t=13* (\ln (1.56))/(\ln (2))\\\\\Rightarrow t=13*0.641=8.34\ hr

User Zeth
by
3.2k points