The number of cans recycled per pund of aluminum recycled in the u. s increased at a relatively constant rate from 1972 to 2002. in 1977 about 23.5 cans per pound of aluminum were recycled. in 2000, about 33.1 cans per pound of aluminum were recycled. a. write an equation that gives the number of cans recycled per pound of aluminum recycled as a function of the number of years since 1972. b. in 2002 there were 53.8 billion aluminum cans collected for recycling. approximately how many pounds of aluminum were collected. explain how you found your answer.