The given information is:
James says 5/5 is greater than 9/10.
A diagram of the problem is:
The first rectangle is divided into 5 parts (given by the denominator), and then we colored 5 of these parts (given by the numerator).
The second rectangle has the same size but it is divided into 10 parts (because of the denominator), and we colored 9 of these parts (because of the numerator).
As you can see, in the first rectangle there is a bigger colored area, thus 5/5 is greater than 9/10.
James is correct.