23, 24, 25, 26, 27, 28, 29
32, 34, 35, 36, 37, 38, 39
42, 43, 45, 46, 47, 48, 49
52, 53, 54, 56, 57, 58, 59
62, 63, 64, 65, 67, 68, 69
72, 73, 74, 75, 76, 78, 79
82, 83, 84, 85, 86, 87, 89
92, 93, 94, 95, 96, 97, 98
So in all there is 56 different two-digit solutions without repetition.