How many different countries serve as headquarters?
select count ( distinct headquarters ) from company
What is the most popular industry?
select industry from company group by industry order by count ( * ) desc limit 1
No, I mean Market_Value_in_Billion.
select name from company order by market_value_in_billion desc limit 1
What headquarter is the most popular?
select headquarters from company group by headquarters order by count ( * ) desc limit 1