Explanation:

Multiple of 72 is 8 and 9
so the number will be divided by 8 and 9
the rule of divisibility of 8 and 9 is applied
when the last three digit is divisible by 8 then the whole numbers are divisible by 8

and the sum of the all digits of the number must be divided by 9
so the number will be divisible by 72
first of all we check this number is divisible by 8
so 24Y on the place of Y what shoulb be??
according to rule...
Y=8 becoz 248 is divisible by 8
then we check by 9
so the sum of all digits =7+4+4+8+2+4+8=37
but the sum must multiple of 9
so it should 45 then
the value of X =45-37=8
therefore X-Y=0

Hence, option 4 is the correct answer.