Question

The 2 digit number which becomes (5/6)th of itself when its digits are reversed. The difference in the digits of the number being $1$ is:

• A. $45$
• B. $54$
• C. $36$
• D. None of these

Answer 1

Answer: (B)

$54$

If the two digits are $x$ and $y$, then the number is $10x+y$
Now $\frac{5}{6}(10x+y)=10y+x$.

Solving,
we get $44x=55y\Rightarrow \frac{x}{y}=\frac{5}{4}$
Also $x-y=1$. Solving them, we get $x=5$ and $y=4$.
Therefore, the number is $54$.