Sum of a positive integer and inverse of another positive integer is 37/4, what will be the sum of integers?

Question

Let a be a single-digit positive integer.
Let n be another positive integer that adjusts itself so that the unit's place digits of n and an + 1 are the same.
Find the sum of all possible values of a.

Answer 1

First no. Is 9
And another 4
9+ 1/4 = 37/4
So sum of integers is 9+4=13

Answer 2

9+1/4 = 37/4
So the numbers are 9 and 4
=> 9+4=13