Answer:
The answer is 10. 
Step-by-step explanation:
There would be 10 players, 2 for each group, and if each player played every other player twice, then that would mean that 20 matches of chess were played. 
Hope this helped!! (:
 
        
             
        
        
        
Answer:
-18
Step-by-step explanation:
Essentially the same as (-6) - 12
 
        
                    
             
        
        
        
9514 1404 393
Answer:
   3.4%
Step-by-step explanation:
The total amount due is ...
   A = P(1 +rt/12) . . . . . principal P, annual rate r, t months
   33829.50 = 28500(1 +66/12r)
   1.187 = 1 +5.5r . . . . . divide by 28500, simplify
   0.185/5.5 = r = 0.034 = 3.4%
The interest rate on the loan is 3.4%.