The symbols ‘$’, ‘&’ and ‘%’ stand for the signs +, – and ×, each symbol for a different sign. Both equations below are correct when worked out by BODMAS.
8 $ 2 & 5 = 21
12 & 3 % 4 = 11
What is the value of 30 % 6 $ 4 & 2?
Answer & explanation
Correct answer: option 4
The correct answer is Option (4) → 8
Test the ways of giving +, – and × to the three symbols against both equations; only one way fits both. Then use the same signs in the new expression.
In 8 $ 2 & 5 = 21, the signs available give \(8\times2+5=21\); the other choices give \(8+2\times5=18\), \(8-2\times5=-2\), \(8\times2-5=11\), \(8+2-5=5\) or \(8-2+5=11\). So ‘$’ is × and ‘&’ is +
The sign left over, –, must be ‘%’
Check: 12 & 3 % 4 \(=12+3-4=11\), which is correct
So 30 % 6 $ 4 & 2 \(=30-6\times4+2=30-24+2=8\)