Know-How Exchange : Student Questions

I suspect others won't want to do your homework for you (as then you won't have the opportunity to learn this stuff before someone hires you with the expectation that you know how to do it).

I would start by plugging something like "Tesco UK" into a search engine and see what shows up. I did this and found an article that gives a good chunk of the information you are looking for within 2 clicks. It would be worth reading the web page of Tesco, just to see what they say, but you may find that articles from business magazines, newspapers, wikipedia, etc. are more likely to provide information about the market as a whole.

Note - my findings says there is at least one more company you should be reporting on (this company also has a market share of at least 10%).