If you want to convert 15.1 into a fraction, you can do it like this:
15 equals to 15/1 and 0.1 equals to 1/10
The result is 15 1/10.
If you want to make it a pure fraction, you have
to make one additional step:
because you want to add 15/1 and 1/10, you
have to get the same denominators, so 15/1 changes to 150/10.
Now, you can add 150/10 and 1/10.
The result is 151/10.