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?

What is the product? (x2+3y+7) [yy+1)

Mr and mrs smith buy tickets for themselves and their four children. the cost of an adult ticket is ? 6 more than the adult ticket. the total cost of the six tickets is ? 40.50 work out the cost of an adult ticket. in your working let c be the cost of the child ticket and a be the cost of the adult ticket.

How many credit hours will a student have to take for the two tuition costs to be equal? round the answer to the nearest tenth of an hour.