An official meeting is attended by 130 department employees. Of them, 66 drink tea, 56 drink coffee and 63 drink juice. 27 can drink either tea or coffee, 25 can drink coffee or juice and 23 can drink juice and tea. 5 employees can drink any of the three. How many drink only tea?

Options

A. 21
B. 22
C. 18
D. 20

Explanation

To solve the problem step by step, we will use the principle of inclusion-exclusion and a Venn diagram approach.

### Step 1: Define the Variables
Let:
- \( T \) = number of employees who drink tea = 66
- \( C \) = number of employees who drink coffee = 56
- \( J \) = number of employees who drink juice = 63
- \( x \) = number of employees who drink tea and coffee = 27
- \( y \) = number of employees who drink coffee and juice = 25
- \( z \) = number of employees who drink juice and tea = 23
- \( e \) = number of employees who drink all three beverages = 5

### Step 2: Set Up the Equations
From the information given:
1. \( x = b + e \) (where \( b \) is the number who drink only tea and coffee)
2. \( y = f + e \) (where \( f \) is the number who drink only coffee and juice)
3. \( z = d + e \) (where \( d \) is the number who drink only juice and tea)

Substituting the value of \( e \):
- \( b + 5 = 27 \) → \( b = 27 - 5 = 22 \)
- \( f + 5 = 25 \) → \( f = 25 - 5 = 20 \)
- \( d + 5 = 23 \) → \( d = 23 - 5 = 18 \)

### Step 3: Total Employees Who Drink Tea
The total number of employees who drink tea can be expressed as:
\[ T = a + b + d + e \]
Where:
- \( a \) = number of employees who drink only tea

Substituting the known values:
\[ 66 = a + 22 + 18 + 5 \]
\[ 66 = a + 45 \]
\[ a = 66 - 45 \]
\[ a = 21 \]

### Conclusion
The number of employees who drink only tea is **21**.