Geometry

Question Analysis
This question tests the algebraic definition of mutual exclusivity using probability formulas.
The focus is on the addition rule for mutually exclusive events: P(X ∪ Y) = P(X) + P(Y) when P(X ∩ Y) = 0.

Key Concept Explanation
For mutually exclusive events, the probability of their union equals the sum of their probabilities, as they have no overlap (P(X ∩ Y) = 0).

Step-by-Step Solution
Given: P(X) + P(Y) = 0.4 + 0.3 = 0.7, and P(X ∪ Y) = 0.7.
Since P(X ∪ Y) = P(X) + P(Y), this satisfies the a...