To solve the problem, we need to find the probability of selecting either a red marble or a blue marble from the bag. This can be done by adding the probabilities of selecting a red marble and a blue marble.
Given:
- The probability of selecting a red marble is [tex]\( \frac{5}{19} \)[/tex].
- The probability of selecting a blue marble is [tex]\( \frac{4}{19} \)[/tex].
The probability of selecting a red or a blue marble is the sum of these two probabilities:
[tex]\[ \text{Probability of red or blue} = \frac{5}{19} + \frac{4}{19} \][/tex]
Since the denominators are the same, we can directly add the numerators:
[tex]\[ \text{Probability of red or blue} = \frac{5 + 4}{19} = \frac{9}{19} \][/tex]
Therefore, the probability of selecting a red or blue marble is [tex]\( \frac{9}{19} \)[/tex].
The correct answer is:
B. [tex]\( \frac{9}{19} \)[/tex]