Different books to arrange on a shelf: 4 blue, 3 green, and 2 red. In how many ways can you select 3 books, one of each color, if the order in which the books are selected does not matter?
2006-10-19 18:57:44 · 2 answers · asked by congosammy 1 in Education & Reference ➔ Homework Help
If the books are one of each color, and you have only three colors, and the order doesn't matter, there there is exactly one way to select three books. BRG = RGB = GRB = BGR = RBG = GBR.
Unless this isn't what you meant, in which case you'll need to be more specific with your question. Did you mean that each book of a single color is different? Like B1, B2, B3, B4? If that's the case, then there are 4 * 3 * 2, which is 24.
2006-10-19 20:58:21 · answer #1 · answered by supensa 6 · 0⤊ 0⤋
While it's not totally clear, I'm pretty sure this is a combinations problem. 4nCr1 * 3nCr1 * 2nCr1. That's just 4*3*2 or 24.
2006-10-20 11:32:06 · answer #2 · answered by dmb 5 · 0⤊ 0⤋