Which set of ordered pairs demonstrates a function?

(3,4) (4,3) (9,7)

Step-by-step explanation:

this represents a function because none of the x's in the x values repeat

(2 1/2)  / (1/4)  = 10
in a real world    scenario;    say  you  have $2.50 and want to divide  into quarters -- how many quarters would you  have?
2.50  /.25  ==?
Another  example -- you  have 2 and a half pizzas you want to give each person at your party 1/4 pie.   Haw many pieces   can you get out of 2 1/2.