What you need to think about is exactly what you are trying to do:
If i is greater than or equal to j output result1. Otherwise, if i is less than two times the value of j output result2.
So what you need to code is just that:
const string result1 = "Foo";
const string result2 = "Bar";
int i = 100;
int j = 100;
string output = "";
if (i >= j)
{
output = result1;
}
else if (i < (2 * j))
{
output = result2;
}
Console.Write(output);