The first part of this problem is to determine how much he will make with the newpapers alone which is 11. Now to get to the 20$ he needs 9 more dollars. for 9 dollars he needs 180 pounds of cans because if you take the 900 pounds it would take in pennies and divide it by 5 which is what you would get with nickels. then to get the amount of cans you multiply 180 by 16 which is the number of ounces in a pound which gives you 2,880 cans. i'm not completely sure but give it a try.
