There are infinite couples of numbers x and y such that x+y < 11, and thus there are infinite possible products of the two numbers.
Here's an example to generate infinite integers: fix [tex] x = 1 [/tex] and choose any value less than 10 for [tex] y [/tex].
So, you have
[tex] x+y = 1+y < 1+10 < 11 \ \text{and } xy = 1\cdot y = y [/tex]
So, for example, you may choose [tex] y = 0,1,2,3,4,5,6,7,8,9 [/tex] and have
[tex] x+y < 11 \ \text{and } xy = 0,1,2,3,4,5,6,7,8,9 [/tex]