Question

A number consists of two digits. If the digits interchange places and the new number is added to the original number, then the resulting number will be divisible by

• A. 5
• B. 3
• C. 9
• D. 11

Answer 1

Answer: (D)

Let the given number be $(10x+y)$ where the ten's digit is x and one(unit)'s digit is y.

Now, the number obtained by interchanging the digits$=(10y+x)$

$\therefore$ On adding these no.'s $=(10x+y)+(10y+x)$

$=11(x+y)$

where $11(x+y)$ is clearly divisible by $11$

Option D$:11$.