Explanation

If the bag contains 5 red bags and 3 blue bags, the total number of bags is:

$$5 + 3 = 8$$

The probability of selecting a red bag is:

$$P(text{Red bag}) = frac{text{Number of red bags}}{text{Total number of bags}} = frac{5}{8}$$

So, the probability is $frac{5}{8}$, which equals 0.625 or 62.5%.