1. ## directly proportional problem

The number N of aluminum cans is directly proportional to the number of people P using 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.

2. Originally Posted by lucky13
The number N of aluminum cans is directly proportional to the number of people P using 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.
The number N of aluminum cans is directly proportional to the number of people P using them.

$\displaystyle N = kP$

250 people use 60,000 cans a year.

$\displaystyle 60000 = k(250)$

$\displaystyle k = 240$

$\displaystyle N = 240P$