The sum of the digits of a two-digit number is $9$. When we intrchange the digits,it is found that the resulting new number is greater than the original number by $27$. What is two digit number?
and we know that :
so $a=6$ and $b=3$
Let the two digits be $x$ and $9-x$. By condition, the reversed no. will be$10(9-x)+x$ and this is 27 more than the previous no. So, $$ $$ $10(9-x)+x=27+(9-x)+10x \implies 90-9x=36+9x \implies 18x=54 \implies x=3,$ so that the other no. is $9-x=9-3=6.$ Got it ???