If * stand for addition
⊗ stand for subtraction
⇔ stand for division
↕ stand for multiplication
≠ stand for equal to
Then which of the following alternatives is correct?
Answer & explanation
Correct answer: option 1
The correct answer is Option (1) → 2 ↕ 5 ⊗ 6 * 2 ≠ 6
Each sign is replaced by the operation it stands for (here ≠ stands for “equal to”), and the left side is then worked out by the BODMAS order: division and multiplication before addition and subtraction. The statement is correct only if both sides come out equal.
Option (1) becomes \(2\times5-6+2=6\)
\(10-6+2=6\), so both sides are 6: correct
Option (2) becomes \(5+7-4\div2=4\)
\(5+7-2=10\), not 4
Option (3) becomes \(3\times6\div2+3-6=5\)
\(9+3-6=6\), not 5
Option (4) becomes \(4\div7+4=2\times3-1\)
Left side \(\displaystyle =\frac{4}{7}+4=4\frac{4}{7}\), right side \(=6-1=5\): not equal
Tip: Option (2) gives 4 only if it is worked from left to right (\(12-4=8\), then \(8\div2=4\)). Always divide before you subtract, whatever the order of the signs.