`54-:3` of `6+9=` ?

Options

A. `117`
B. `12`
C. `(6)/(5)`
D. none of these

Answer

To solve the expression `54 -: 3 of 6 + 9`, we will follow the order of operations known as BODMAS/BIDMAS. This stands for Brackets, Orders (i.e., powers and roots, etc.), Division and Multiplication (from left to right), Addition and Subtraction (from left to right).

### Step-by-Step Solution:

1. **Identify the expression**:
The expression we need to simplify is `54 -: 3 of 6 + 9`.

2. **Understand the term "of"**:
The term "of" in mathematical expressions usually means multiplication. Therefore, we can rewrite `3 of 6` as `3 * 6`.

3. **Rewrite the expression**:
The expression now becomes `54 -: (3 * 6) + 9`.

4. **Calculate `3 * 6`**:
First, we calculate `3 * 6`:
\[ 3 * 6 = 18 \]
Now the expression is `54 -: 18 + 9`.

5. **Perform the division**:
Next, we perform the division `54 -: 18`:
\[ 54 ÷ 18 = 3 \]
Now the expression is `3 + 9`.

6. **Perform the addition**:
Finally, we add `3 + 9`:
\[ 3 + 9 = 12 \]

### Final Answer:
The final answer is **12**.

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