Difficulty: Medium
Correct Answer: 56
Explanation:
Introduction / Context:
Translate each symbol to its true operation, then compute with standard precedence rules. Carefully track each mapping to avoid mistakes.
Given Data / Assumptions:
Concept / Approach:
Replace first, then evaluate ×/÷ (i.e., the real operations after mapping), finally do +/−.
Step-by-Step Solution:
Verification / Alternative check:
Regrouping as (90 ÷ 18) × 6 + (30 − 4) = 30 + 26 = 56 confirms the result.
Why Other Options Are Wrong:
They come from wrong replacements or ignoring precedence.
Common Pitfalls:
Final Answer:
56
Discussion & Comments