If “+” means “÷”, “−” means “+”, “×” means “−” and “÷” means “×”, evaluate: 24 ÷ 12 − 18 + 9

Difficulty: Easy

Correct Answer: 290

Explanation:

Introduction / Context:We replace each printed operator with its new meaning and then evaluate with standard precedence.

Given Data / Assumptions:

  • Mappings: “+”→“÷”, “−”→“+”, “×”→“−”, “÷”→“×”.
  • Expression: 24 ÷ 12 − 18 + 9.

Concept / Approach:First rewrite the expression with the true operations, then compute using precedence.

Step-by-Step Solution:24 ÷ 12 becomes 24 × 12 (since ÷→×).“− 18” becomes “+ 18”. “+ 9” becomes “÷ 9”.So value = 24 × 12 + 18 ÷ 9 = 288 + 2 = 290.

Verification / Alternative check:Checking each option shows only 290 matches the evaluated result.

Why Other Options Are Wrong:They correspond to arithmetic done before remapping or with wrong precedence.

Common Pitfalls:Treating the printed operators literally instead of applying the mapping.

Final Answer:290.

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