To solve this problem, we need to determine the number of bacteria in 100 milliliters of water, given that there are about 1,500,000 bacteria in 1 milliliter.
We start by identifying how many bacteria are in one milliliter:
- There are 1,500,000 bacteria in 1 milliliter.
Next, we need to calculate the number of bacteria in 100 milliliters. Given that each milliliter contains 1,500,000 bacteria, we multiply the number of bacteria in one milliliter by the number of milliliters:
[tex]\[
\text{Number of bacteria in 100 milliliters} = 1,500,000 \text{ bacteria/milliliter} \times 100 \text{ milliliters}
\][/tex]
Performing the multiplication:
[tex]\[
1,500,000 \times 100 = 150,000,000
\][/tex]
Thus, the number of bacteria in 100 milliliters of water is 150,000,000. In scientific notation, this can be represented as:
[tex]\[
1.5 \times 10^8
\][/tex]
Therefore, the correct answer is:
E. [tex]\(1.5 \times 10^8\)[/tex]