Question

If \(a+b\) means \(a-b\), \(a-b\) means \(a \times b\), \(a \times b\) means \(a/b\), \(a/b\) means \(a+b\), then what is the value of \(10+30-100\times50/25\)?

• A. 15
• B. -25
• C. -15
• D. 0

Hint:

In operator replacement problems: Always substitute symbols first, then apply BODMAS. Never solve directly without replacing operators.

Answer 1

The Correct Option is B

Concept: In such questions, the mathematical operators do not carry their usual meanings. We first replace each symbol with its new meaning according to the given conditions.

• \(+\) means \( - \)

• \(-\) means \( \times \)

• \(\times\) means \( / \)

• \(/\) means \( + \)
Step 1: Write the given expression.
\[ 10+30-100\times50/25 \]

Step 2: Replace each operator by its actual meaning.
Using the rules: \[ 10+30 \Rightarrow 10-30 \] \[ -100 \Rightarrow \times100 \] \[ \times50 \Rightarrow /50 \] \[ /25 \Rightarrow +25 \] So the new expression becomes: \[ 10-30\times100/50+25 \]

Step 3: Apply BODMAS rule.
First multiplication and division: \[ 30\times100=3000 \] \[ 3000/50=60 \] So: \[ 10-60+25 \]

Step 4: Solve left to right.
\[ 10-60=-50 \] \[ -50+25=-25 \]

Step 5: Final conclusion.
Hence, the correct answer is: \[ \boxed{-25} \]