Question

A number consists of two digits, the sum of the digits being $12$. If $18$ is subtracted from the number, the digits are reversed. Find the number.

• A. $75$
• B. $45$
• C. $65$
• D. $95$

Answer 1

Answer: (A)

Let the two digits number be $10y+x$.
where $x$ and $y$ are two digits
When number is reversed it becomes $10x+y$
Sum of two digits $=x+y$
Then, the equations formed are
$10y+x-18=10x+y$
$y-x=2$ ......(1)
Also, $x+y=12$ .....(2)
Adding equation (1) and (2), we get
$x=5$ and $y=7$
Hence, the number is $75$.