The doubling period of a bacterial population is 15 minutes. At time \( t=80 \) minutes, the bacterial population was 60000 . What was the initial population at time \( t=0 \) ? Find the size of the bacterial population after 4 hours.

Indicate between which two integers the following root lies \( ?<\sqrt{13}< \) ?

A population of a bacteria colony doubles every 3 hours. If there are currently 500 bacteria, how many will there be after 12 hours?

Resolver: a) \( \frac{5}{8} \cdot\left(\frac{1}{4}\right)^{-1}+\frac{9}{5} \cdot \sqrt{\frac{27}{9} \cdot 3}-\frac{7}{10}+0,8= \)

Hisoblang: \( \sqrt{66^{2}-44^{2}-22^{2}} \) \( \begin{array}{llll}\text { A) } 22 & \text { B) } 44 & \text { C) } 0 & \text { D) } 33\end{array} \)

2. The value of \( \frac{(0.1)^{2}-(0.01)^{2}}{0.0001}+1 \) is