The probabilities of two events are 0.25 and 0.50. The total probability of both happening together is 0.14. The probability of none of the events happening ?

Answer

To find the probability of none of the events happening, we will use the probabilities of the events and the formula for the union of two events. Let's denote the events as follows:

- Let \( P(A) = 0.25 \) (Probability of event A)
- Let \( P(B) = 0.50 \) (Probability of event B)
- Let \( P(A \cap B) = 0.14 \) (Probability of both events happening together)

### Step-by-Step Solution:

1. **Calculate the Probability of A Union B**:
The formula for the probability of the union of two events is given by:
\[ P(A \cup B) = P(A) + P(B) - P(A \cap B) \]
Substituting the values:
\[ P(A \cup B) = 0.25 + 0.50 - 0.14 \]
\[ P(A \cup B) = 0.75 - 0.14 = 0.61 \]

2. **Calculate the Probability of None of the Events Happening**:
The probability of none of the events happening is the complement of the probability of at least one of the events happening. This can be calculated as:
\[ P(\text{none of A or B}) = 1 - P(A \cup B) \]
Substituting the value we found for \( P(A \cup B) \):
\[ P(\text{none of A or B}) = 1 - 0.61 = 0.39 \]

### Final Answer:
The probability of none of the events happening is \( \boxed{0.39} \).