*963.To find the answer, let’s:
1.First, let’s find all two digit numbers whose sum is 9. They are,{18,27,36,45,54,63,72,81,90}
2.Next let’s write each number  with their counterparts in reverse order
{18,81},{27,72},{36,63},{45,54},{90,09}
3.it is said that if the number is divided by itself in reverse order, the result is six-fifths or 6/5,so let’s divide the numbers in the curly brackets.
{18/81=2/9, 81/18=9/2},{ 27/72=3/8, 72/27=8/3},{36/63=4/7,63/36=7/4}, {45/54=5/6,54/45=6/5} ,{90/09=10,09/90=1/10}
4.The only number whose two digits add up to 9 and when divided by itself in reverse order = six fifths is 54.54 divided by 45 =6/5, so 54 is the number.