Answer: 0.58

The correct answer is A (0.58). **Explanation:** This is a probability question involving the union of two events. The formula for the probability of either event A or event B occurring is: P(A ∪ B) = P(A) + P(B) - P(A ∩ B) Where: - P(A) = probability of Apple's share price declining by more than 5% = 0.4 - P(B) = probability of Microsoft's share price declining by more than 5% = 0.3 - P(A ∩ B) = probability that both Apple and Microsoft share prices decline by more than 5% Assuming the events are independent (which is reasonable for two different companies), we can calculate: P(A ∩ B) = P(A) × P(B) = 0.4 × 0.3 = 0.12 Therefore: P(A ∪ B) = 0.4 + 0.3 - 0.12 = 0.58 **Why other options are incorrect:** - **B (0.12)**: This is the probability that both events occur (intersection), not either event (union). - **C (0.7)**: This would be the sum of probabilities (0.4 + 0.3) without subtracting the intersection, which double-counts the scenario where both events occur. - **D (0.67)**: This is not the correct calculation for the union of independent events. **Key Concept:** When calculating the probability of either of two events occurring, you must subtract the probability that both occur to avoid double-counting that scenario.

Author: Nikitesh Somanthe