You can buy 3 post cards for $5.40 , 6 post cards for $10.80 or 9 postcards for $16.20.what is the constant of proportionality for buying post cards?

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.

Pat listed all the numbers that have 15 as a multiple write the numbers in pats list

What is the relationship between all triangles that can be drawn given the same three angles