Evaluate: `50 times (-5) +540 div [100-{80-(20 times 2)}]`

Options

A. `-351`
B. `-731`
C. `-351`
D. `-241`

Answer

To evaluate the expression `50 times (-5) + 540 div [100 - {80 - (20 times 2)}]`, we will follow the order of operations, often remembered by the acronym PEMDAS (Parentheses, Exponents, Multiplication and Division (from left to right), Addition and Subtraction (from left to right)).

### Step-by-Step Solution:

1. **Evaluate the innermost parentheses**:
- Calculate \(20 \times 2\):
\[ 20 \times 2 = 40 \]
- Now substitute this back into the expression:
\[ 50 \times (-5) + 540 \div [100 - (80 - 40)] \]

2. **Continue with the parentheses**:
- Calculate \(80 - 40\):
\[ 80 - 40 = 40 \]
- Substitute this back into the expression:
\[ 50 \times (-5) + 540 \div [100 - 40] \]

3. **Evaluate the remaining expression in the brackets**:
- Calculate \(100 - 40\):
\[ 100 - 40 = 60 \]
- Substitute this back into the expression:
\[ 50 \times (-5) + 540 \div 60 \]

4. **Perform the division**:
- Calculate \(540 \div 60\):
\[ 540 \div 60 = 9 \]
- Substitute this back into the expression:
\[ 50 \times (-5) + 9 \]

5. **Perform the multiplication**:
- Calculate \(50 \times (-5)\):
\[ 50 \times (-5) = -250 \]
- Substitute this back into the expression:
\[ -250 + 9 \]

6. **Finally, perform the addition**:
- Calculate \(-250 + 9\):
\[ -250 + 9 = -241 \]

### Final Answer:
\[ \text{The final answer is } -241. \]