The numberNof aluminum cans is directly proportional to the number of peoplePusing them.

It is known that 250 people use 60,000 cans a year.

What is an equation of variation expessing N as a function of P?

I know x and y (in this case 250 and 60,000) are directly proportional if y=kx..or something like that i honestly am confused about this one, help please.