a number of two digits in such that four times the unit digit is greater than thrice the tens digits, when the digits are reversed the number is increased by 9. find the number​

The first one, i believe, would be correct. all the others have one thing in common, and that's that they have repeating numbers. in the second one, x and y have repeating 6's and 3's, and in the third, x and y have repeating 6's as well. in the last one, there are repeating 3's. the first one has no repeating numbers.