data management (gr.12)
posted by nat .
how many different sums of money can you make with a penny, a dime, a onedollar coin, and a twodollar coin?

One, because if you add them up in different order you're still going to get the same answer.(if I understood the question correctly)

well the answer in the textbook is 15? :S i don't know, it's in the unit of combinations and the binomial theorem

2^n1=2^41=15
2 is always the base (you either pick it or you don't) and 4 because there are 4 options and subtract one because you exclude the empty or null set.