Ted’s class collects aluminum cans to sell to the recycling center. the center pays $0.002 for each kilogram of aluminum.
write a formula that ted determine how much money his class will receive for the cans.
let's let
t=total amount they'll recieve
n=number of kilograms of cans

There are several information's of immense importance already given in the question. Based on these information's the answer can be easily deduced. Let us now focus on the problem in hand.

Amount paid by the center per kilogram of aluminium = $0.002
The equation is
t = 0.002n dollars

I hope it is absolutely clear to you.