\( \definecolor{colordef}{RGB}{249,49,84} \definecolor{colorprop}{RGB}{18,102,241} \)
Let \( P(C) = 0.4 \) and \( P(D) = 0.5 \). Assume that events \( C \) and \( D \) are mutually exclusive.
Calculate \( P(C \text{ or } D) \).
\( P(C \text{ or } D) = \)