Evaluate the below expression
`21 + [5 " of " {15 + (18-17)}]`
(a)100
(b)99
(c)102
(d)101

Options

A. 100
B. 99
C. 102
D. 101

Answer

To evaluate the expression \( 21 + [5 \text{ of } \{15 + (18-17)\}] \), we will follow the order of operations, often remembered by the acronym BODMAS/BIDMAS (Brackets, Orders, Division and Multiplication, Addition and Subtraction).

### Step-by-Step Solution:

1. **Evaluate the innermost bracket**:
\[ (18 - 17) = 1 \]
Now, the expression becomes:
\[ 21 + [5 \text{ of } \{15 + 1\}] \]

**Hint**: Always start with the innermost brackets first.

2. **Evaluate the next bracket**:
\[ 15 + 1 = 16 \]
Now, the expression updates to:
\[ 21 + [5 \text{ of } 16] \]

**Hint**: After resolving the innermost bracket, move outward to the next bracket.

3. **Evaluate "of" (which means multiplication)**:
\[ 5 \text{ of } 16 = 5 \times 16 = 80 \]
Now, the expression simplifies to:
\[ 21 + 80 \]

**Hint**: The term "of" in mathematical expressions typically indicates multiplication.

4. **Final addition**:
\[ 21 + 80 = 101 \]

**Hint**: After resolving all operations, perform the final addition to find the result.

### Final Answer:
The value of the expression is \( 101 \), which corresponds to option (d).