If 'A' means '-', 'B' means '÷', 'C' means '+', and 'D' means '×'
what is the value of the following expression?
25 B 5 C 3 D 2 A 4=?
A7
B14
C21
D28
Answer:
A. 7
Read Explanation:
Step-by-Step Calculation
- Substitute the symbols: Replace the letters with their respective mathematical operators:
- A = -
- B = ÷
- C = +
- D = ×
- The expression becomes: 25 ÷ 5 + 3 × 2 - 4
- Apply BODMAS/PEMDAS Rule: To solve this, adhere to the standard order of operations:
- Division: Perform the division first: 25 ÷ 5 = 5. The equation is now 5 + 3 × 2 - 4.
- Multiplication: Perform the multiplication next: 3 × 2 = 6. The equation is now 5 + 6 - 4.
- Addition: Perform the addition: 5 + 6 = 11. The equation is now 11 - 4.
- Subtraction: Finally, perform the subtraction: 11 - 4 = 7.
Key Concepts for Competitive Exams
- BODMAS Rule: Always prioritize brackets, order (powers/roots), division, multiplication, addition, and subtraction in that exact sequence to avoid calculation errors.
- Accuracy vs. Speed: In mental ability sections, errors often occur during the substitution phase; write down the converted expression clearly before calculating.
- Practice Tip: For problems involving multiple operators, break the expression into segments to prevent missing a step or miscalculating the order of precedence.