### A student finds the average of 10, 2 digits numbers. If the digits of one of the numbers interchanged, the average increases by 3.6. The difference between the digits of the 2 digits number is :

**A.** 4

**B.** 3

**C.** 2

**D.** 5

## Show Answer

###
Answer-A

Solution-

Solution(By Apex Team)

According to the question,
Let as consider by mistake he writes 10th number with its digits interchanged
$\begin{array}{l}\therefore\left[\Large\frac{10x+y-(10y+x)}{10}\right]=3.6\end{array}$
∴ In these remaining nine numbers are same and they cancel out
$\begin{array}{l}\Rightarrow\left[\Large\frac{10x+y-(10y+x)}{10}\right]=3.6\\
\Rightarrow9x-9y=36\\
\Rightarrow x-y=4\end{array}$