A boy was asked to multiply a number by 25, but by mistake he multiplied it by 45. His answer was 200 more than the correct answer. What was the number?
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → 10
Multiplying by 45 instead of 25 adds \(45-25=20\) times the number to the result, and this extra amount is 200.
Let the number be \(x\)
\(45x-25x=200\)
\(20x=200\), so \(x=10\)
Check: \(450-250=200\). The number was 10.