Molecular plus 1 is 1. So the numerator is one less than the denominator, and such numbers are 1/2, 2/3, 3/4, 4/5, 5/6, 6/7, etc.

Such a number, the denominator plus 1 is 3/4, only 6/7, and the denominator plus 1 is 6/8, which is simplified to 3/4.

Or the denominator plus 1 is 3/4, then the denominator plus 1 may be 3/4, 6/8, 9/ 12 and so on.

Because the numerator is 1 after adding 1, the numerator is one less than the denominator, so this is the number in which the denominator minus 1 is greater than the numerator.