If # = ×, @ = −, $ = +, then evaluate: 9 # 2 @ 3 $ 1

Correct — C. Rule: swap each symbol for its operator, then apply BODMAS.

Printed: 9 # 2 @ 3 $ 1
Substituted: 9 × 2 − 3 + 1

Multiplication first: 9 × 2 = 18
Then left to right: 18 − 3 = 15, and 15 + 1 = 16 → option (c).

Why the others are wrong

• (a)
  18 — 18 is only the product 9 × 2. The − 3 and + 1 still have to be applied, and they bring the value down to 16.
• (b)
  14 — 14 comes from adding before subtracting, 18 − (3 + 1). Subtraction and addition share a rank, so they run left to right: 18 − 3 first, then + 1.
• (d)
  17 — 17 does not come from any grouping of 9 × 2 − 3 + 1. Left to right gives 16, and grouping the last two terms gives 14.

A symbol-substitution item tests two things in order: swap every symbol correctly, then evaluate under BODMAS (brackets, orders, division and multiplication, addition and subtraction).

Division and multiplication share a rank and run left to right. So do addition and subtraction: when both appear, work left to right.

Doing the + before the − changes the answer here, from 16 to 14.

Key facts

• Here # stands for ×, @ for − and $ for +.
• 9 × 2 − 3 + 1 = 16 when worked by BODMAS.
• Operators of equal rank, × with ÷ or + with −, are worked left to right.

Common traps

• Doing the addition before the subtraction, which gives 14.
• Evaluating 9 × 2 and forgetting the remaining operations, which gives 18.

No directly related past PYQ was found.