Some countries have only a Athlete and others like the USA have 530 see related link
2012
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.
There do not have the same number in each country
flower
part of the cauldron
It varied with the country from as little as two for 11 countries to the 530 for the USA
No one 'wins' the Olympics. There are dozens of different events that competitors participate in and each individual event has a winner.
It is based on how well they do in the qualifications or if they choose not to do a qualification round. Other times its alphabetical order by country or name
During the pre Olympics , each athalete must do well and qualify to reach the Olympics from each country.
approximately how many competitors will compete at the london olympic games?
205 countries participated in the 2012 London Olympics according to the official London Olympics web site with a total of 10,961 athletes. See related links below for the list of countries and number of athletes from each country.
The 12 women and 12 men with the best scores advance to the final round. But at the starting, each country can have 2 or 3 competitors.