Interchange one pair of signs to make the equation true: 15 ÷ 9 × 3 − 74 + 2 = 5

Difficulty: Medium

Correct Answer: + and ÷

Explanation:

Introduction / Context:We must find which global swap of a listed pair of operators makes the given equality hold.

Given Data / Assumptions:

  • Expression: 15 ÷ 9 × 3 − 74 + 2.
  • Goal: value equals 5.

Concept / Approach:Test each candidate swap and compute with precedence.

Step-by-Step Solution:Swap “+” and “÷” (Option C): becomes 15 + 9 × 3 − 74 ÷ 2.Compute: 9 × 3 = 27; 15 + 27 = 42; 74 ÷ 2 = 37; 42 − 37 = 5 ✔.

Verification / Alternative check:Other swaps yield values far from 5.

Why Other Options Are Wrong:They either significantly increase or decrease the total beyond 5.

Common Pitfalls:Ignoring operator precedence when evaluating the swapped expression.

Final Answer:+ and ÷.

More Questions from Mathematical Operations

Discussion & Comments

No comments yet. Be the first to comment!
Join Discussion