If ‘+' means 'x', '-' means '÷', 'x' means '-' and '÷' means '+', then 4 ÷ 8 – 2 x 2 + 4 = ?

Start by swapping every symbol with its assigned meaning, one at a time. The question gives + = x, - = ÷, x = - and ÷ = +. Applying these to 4 ÷ 8 – 2 x 2 + 4 gives 4 + 8 ÷ 2 - 2 × 4.

Now apply the normal BODMAS order. Division and multiplication come first: 8 ÷ 2 = 4 and 2 × 4 = 8. The expression becomes 4 + 4 - 8 = 0, so the answer is B.

• A) 4 is wrong. It comes from evaluating left to right without respecting precedence.
• C) 8 is wrong. It comes from taking 2 × 4 as 8 but skipping the division, or from a similar slip in the order of operations.
• D) 6 is wrong. It comes from misreading one substituted sign, most often the final + that should be ×.

Core concept: symbol substitution followed by BODMAS. This is a standard reasoning and mental-ability skill in UPPSC Prelims, and the same discipline of working through operations in order helps in data-interpretation and calculation questions.

Trap: aspirants evaluate strictly left to right after substitution (giving 16 or 4), forgetting that multiplication and division bind before addition and subtraction.