Question

The digits of tens place of a two digit number is three times that in the units place. If the digits are reversed, the new number will be $36$ less than the original number. find the original number

Answer 1

Let say ‘$x$' is digit on one's place, so $3x$ is digit on tens' place.

So number is $(10\times 3x)+x=31x$

Now, if reverse the position of digit, new number is $(10\times x)+3x=10x+3=13x$

As given new number is less by $36$ from old number.

$\Rightarrow 31x-36=13x$

$\Rightarrow 18x=36$
$\therefore x=2$

So, the required number is $(10\times 3\times 2)+2=60+2=62$.