In a tennis tournament each athlete plays one match against each of the other athletes. there are 12 athletes scheduled to play in the tournament. how many matches will be played? also someone figure out these three problems

The ivring berlin learning center would like a possible net profit of $650,000 on its new resource manual it sells to schools. the fixed costs for producing the manual are $780,000 and the variable cost per package is $19.85. if the estimated unit sales are 1,250,000 units, what selling price unit should the ivring berlin learning center try?