Let the original number by xy According to given condition (10x + y) > 4(10y + x) 6x – 39y > 0 On putting y = 1 x has to be more than or equal to 7 So for y = 1, Possible values for x are 7, 8, 9 So, 3 numbers are possible when y is 1 (71), (81), (91) Values greater than 1 are not possible for y. So there are 3 possible numbers.