Preston adopted a cat from a rescue shelter. He needs to buy some cat litter, so he compares prices at different stores. He finds the best deal at Fluffy Felines Pet Shop, which sells a 20-pound jug of cat litter for $8.60. How much does the cat litter cost per pound?

A pound of litter cost 0.43
You would find this by dividing the 8.60 by the 20 to get to the final answer of 0.43

the law of definite proportions states samples of a compound will always contain the same proportion of elements by mass. in other words, a given compound will always contain the same elements in the same proportions by mass.the law of multiple proportions states when two elements combine with each other to form more than one compound, then the weights of one element that combine with a fixed weight of the other are in a ratio of small whole numbers.

I'm gonna have to say about 13 percent