There are a total of 380 competitors in 23 sports competing for China at the 2012 Summer Olympics.
Italy were competitors in the 2012 Olympics.
4 of them
The answer is 12 - as usual, double the number of rings in the logo (of which each half-ring represents a single competitor). The number of rings, and hence competitors, doubles at each Olympics. This means at the 2012 London Olympics there will be a total of 45 competitors.
200.000 will compete