What is the value of the following expression?
108 `div 18 xx 3-64 xx 2 div 32 + 80 div 5` of 4

Options

A. 78
B. 62
C. 2
D. 18

Answer

To solve the expression \( 108 \div 18 \times 3 - 64 \times 2 \div 32 + 80 \div 5 \text{ of } 4 \), we will follow the order of operations, also known as BODMAS/BIDMAS (Brackets, Orders, Division and Multiplication (from left to right), Addition and Subtraction (from left to right)).

### Step-by-Step Solution:

1. **Identify the 'of' operation**:
The expression contains "of 4" at the end, which means we need to multiply 80 by 4.
\[ 80 \div 5 \text{ of } 4 = 80 \div 5 \times 4 \]

2. **Calculate \( 80 \div 5 \)**:
\[ 80 \div 5 = 16 \]
So, now we have:
\[ 108 \div 18 \times 3 - 64 \times 2 \div 32 + 16 \]

3. **Calculate \( 108 \div 18 \)**:
\[ 108 \div 18 = 6 \]
Now the expression is:
\[ 6 \times 3 - 64 \times 2 \div 32 + 16 \]

4. **Calculate \( 6 \times 3 \)**:
\[ 6 \times 3 = 18 \]
Now the expression is:
\[ 18 - 64 \times 2 \div 32 + 16 \]

5. **Calculate \( 64 \times 2 \)**:
\[ 64 \times 2 = 128 \]
Now the expression is:
\[ 18 - 128 \div 32 + 16 \]

6. **Calculate \( 128 \div 32 \)**:
\[ 128 \div 32 = 4 \]
Now the expression is:
\[ 18 - 4 + 16 \]

7. **Perform the subtraction and addition**:
- First, perform the subtraction:
\[ 18 - 4 = 14 \]
- Then, add 16:
\[ 14 + 16 = 30 \]

### Final Result:
The value of the expression is \( 30 \).