If 'A' stands for '÷', 'B' stands for '×', 'C' stands for '+' and 'D' stands for '-' , what will come in place of the question mark (?) in the following equation?

6 B 4 D 30 A 5 C 12 = ? D 4

1. A

   32

2. B

   34

3. C

   36

4. D

   38

Appeared in: Bihar NHM CHO-2025

Explanation

• The problem requires substituting given letters with their corresponding mathematical operators and then solving the resulting arithmetic equation.
• The core principle for solving is the BODMAS rule, which dictates the order of operations: Division and Multiplication are performed before Addition and Subtraction.
• Substituting the operators gives the equation: 6 × 4 - 30 ÷ 5 + 12 = ? - 4.
• Following BODMAS, the left side is calculated as (6 × 4) - (30 ÷ 5) + 12, which simplifies to 24 - 6 + 12 = 30.
• The final equation becomes 30 = ? - 4. Solving for '?' by adding 4 to 30 gives the answer 34.

Why Other Options Were Wrong

• Option A: This is an incorrect result, likely due to a calculation error after correctly applying the BODMAS rule. For instance, if the left side was incorrectly calculated as 28 (e.g., 24 - 6 + 10), then solving 28 = ? - 4 would yield 32.
• Option C: This value would be obtained if there was a calculation error, such as incorrectly calculating the left side of the equation as 32. Solving 32 = ? - 4 would result in 36.
• Option D: This answer suggests a calculation error. If the left side of the equation was mistakenly calculated to be 34, then solving 34 = ? - 4 would lead to an answer of 38.

Related Visual

• Visual 1: Infographic: Explaining the BODMAS/PEMDAS rule with a worked example, showing the hierarchy of operations from Brackets/Parentheses to Addition/Subtraction.

Clinical Relevance

• Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Mathematical Reasoning and Order of Operations (BODMAS) as background academic context rather than a clinical decision trigger.
• While not a direct clinical question, strong logical and mathematical reasoning is a critical skill for nurses.
• This skill is essential for accurate drug dosage calculations, IV drip rate adjustments, and interpreting patient data, all of which are vital for patient safety.
• What if? If the operator 'D' stood for addition (+) and 'C' for subtraction (-), the LHS would be 6x4 + 30/5 - 12 = 24 + 6 - 12 = 18. The equation would be 18 = ? + 4, making ? = 14.

How to Approach the Question

• First, carefully read the question to understand the substitution rule for each letter (A, B, C, D) with its corresponding mathematical operator (+, -, ×, ÷).
• Rewrite the entire equation on paper, replacing the letters with the correct operators to create a clear arithmetic problem.
• Identify that the equation must be solved using the order of operations, commonly known as the BODMAS/PEMDAS rule (Brackets, Orders, Division/Multiplication, Addition/Subtraction).
• Systematically solve the left-hand side (LHS) of the equation by performing division and multiplication first, followed by addition and subtraction.
• Once the LHS is simplified to a single number, set up the final simple equation (e.g., 30 = ? - 4).
• Solve for the unknown value ('?') by isolating it on one side of the equation.

Concept Tested & Keywords

• Concept Tested: Mathematical Reasoning and Order of Operations (BODMAS)
• Stem keywords: mathematical operators, equation, BODMAS rule
• Lead-in keywords: what will come in place of

Question ID

QGsT3-cxrUCN_jqI8YMOFt

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