In a city , here are 25 Hindi medium schools , 18 English medium schools and 7 schools have both the medium . Find
how many schools have English medium only :

Answer

To find the number of schools that have English medium only, we can follow these steps:

### Step 1: Identify the given information
- Number of Hindi medium schools (A) = 25
- Number of English medium schools (B) = 18
- Number of schools that have both mediums (A ∩ B) = 7

### Step 2: Use the formula for the union of two sets
We can use the formula for the union of two sets to find the total number of schools:
\[ N(A \cup B) = N(A) + N(B) - N(A \cap B) \]
Where:
- \( N(A \cup B) \) = Total number of schools with at least one medium
- \( N(A) \) = Number of Hindi medium schools
- \( N(B) \) = Number of English medium schools
- \( N(A \cap B) \) = Number of schools with both mediums

### Step 3: Substitute the values into the formula
Substituting the given values into the formula:
\[ N(A \cup B) = 25 + 18 - 7 \]

### Step 4: Calculate the total number of schools
Now, perform the calculation:
\[ N(A \cup B) = 25 + 18 - 7 = 36 \]

### Step 5: Find the number of English medium only schools
To find the number of schools that have English medium only, we can use the formula:
\[ N(B \text{ only}) = N(B) - N(A \cap B) \]
Substituting the values:
\[ N(B \text{ only}) = 18 - 7 \]

### Step 6: Calculate the number of English medium only schools
Now, perform the calculation:
\[ N(B \text{ only}) = 18 - 7 = 11 \]

### Final Answer
The number of schools that have English medium only is **11**.

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