There are 20 players in a table tennis competition. each player must play exactly one match against every other player. how many matches are there in the competition?

Step-by-step explanation:

number of games = 20(19)/2 = 190

We have to divide by 2 since games like A vs B and B vs A are the same game.

22 and 22

step-by-step explanation:

10 plus 12 equals 22.

12 plus 10 also equals 22 because regardless of what order they're in, they're gonna equal the same thing.

1/3 + 1/3 ≠ 2/6 because 1/3 alone = 2/6  

step by step explanation:

1/3 + 1/3 = 2/3       2/3=4/6