If `E_(1) and E_(2)` are two events and `E_(2)` is a subset of `E_(1)` then `P(E_(1)//E_(2))`=_____

Answer

To solve the problem, we need to find the conditional probability \( P(E_1 | E_2) \) given that \( E_2 \) is a subset of \( E_1 \).

### Step-by-step Solution:

1. **Understanding Conditional Probability**:
The formula for conditional probability is given by:
\[ P(E_1 | E_2) = \frac{P(E_1 \cap E_2)}{P(E_2)} \]
where \( P(E_1 \cap E_2) \) is the probability of both events \( E_1 \) and \( E_2 \) occurring.

2. **Using the Subset Relationship**:
Since \( E_2 \) is a subset of \( E_1 \), it follows that every outcome in \( E_2 \) is also in \( E_1 \). Therefore, the intersection \( E_1 \cap E_2 \) is simply \( E_2 \):
\[ P(E_1 \cap E_2) = P(E_2) \]

3. **Substituting into the Conditional Probability Formula**:
Now, substituting \( P(E_1 \cap E_2) \) into the conditional probability formula:
\[ P(E_1 | E_2) = \frac{P(E_2)}{P(E_2)} \]

4. **Simplifying the Expression**:
Since \( P(E_2) \) is in both the numerator and the denominator, we can simplify:
\[ P(E_1 | E_2) = 1 \]

### Final Answer:
Thus, the value of \( P(E_1 | E_2) \) is:
\[ \boxed{1} \]