If A = ÷, B = +, C = - and D = x, then which of the following is correct ?

Substitute the symbols first: A is ÷, B is +, C is −, D is ×. Then test each option using standard order of operations (multiplication and division before addition and subtraction, and left to right for equal-precedence operators).

Option D is correct: 108 − 72 = 36, and 78 − 42 = 36. Both sides match.

• Option A is wrong: 24 ÷ 6 + 10 = 14, but 5 × 6 − 12 = 18.
• Option B is wrong: 6 ÷ 4 × 6 = 9, but 4 + 2 × 6 = 16 under BODMAS (36 only if you wrongly add first).
• Option C is wrong: 30 × 4 ÷ 12 = 10, but 30 ÷ 12 × 4 ÷ 5 = 2.

The core concept is symbol substitution combined with BODMAS and left-to-right evaluation. This is basic numerical and logical reasoning, the kind of quick, accurate arithmetic that also helps in data interpretation questions in Paper II and in Mains essay and case-based numerical problems.

Trap: Aspirants often evaluate strictly by sight or add before multiplying, which can make Option B appear to balance. Always apply precedence before comparing both sides.