Bacteria Growth
1. **State the problem:** We want to find the time $h$ it takes for the bacteria colonies to grow from 10 to 15,080 given the growth rate is 5% per hour.
2. **Write the formula:** The number of bacteria colonies after $h$ hours is given by
$$N(h) = B \cdot r^{2h}$$
where $B$ is the initial amount, $r$ is the growth rate factor, and $h$ is the time in hours.
3. **Identify given values:**
- Initial colonies $B = 10$
- Growth rate $5\% = 0.05$, so $r = 1 + 0.05 = 1.05$
- Final colonies $N(h) = 15,080$
4. **Set up the equation:**
$$15,080 = 10 \cdot (1.05)^{2h}$$
5. **Isolate the exponential term:**
$$\frac{15,080}{10} = (1.05)^{2h}$$
$$1,508 = (1.05)^{2h}$$
6. **Take the natural logarithm of both sides:**
$$\ln(1,508) = \ln\left((1.05)^{2h}\right)$$
7. **Use logarithm power rule:**
$$\ln(1,508) = 2h \cdot \ln(1.05)$$
8. **Solve for $h$:**
$$h = \frac{\ln(1,508)}{2 \cdot \ln(1.05)}$$
9. **Calculate values:**
$$\ln(1,508) \approx 7.318$$
$$\ln(1.05) \approx 0.04879$$
10. **Final calculation:**
$$h = \frac{7.318}{2 \times 0.04879} = \frac{7.318}{0.09758} \approx 75.0$$
**Answer:** It will take approximately **75 hours** for the bacteria colonies to grow to 15,080.