There are 85 mini chocolates in a bowl. The ratio of kit kats to Hersheys bars is 8:7. About how many Kit Kats were there? an estimate

C(17, 11) is the answer======the initial expression  c(17, 6) says that you have 17 items and you are choosing 6 of them: how many ways are there to choose 6 of them? when you choose 6 items, you leave 11 items behind. so it's the same as asking: how many ways are there to not choose 11 items? c(17, 11) is equivalent.alternatively, here's an algebraic proof: since      then    and    it is equivalent to c(17,6) because multiplication order does not matter.