So five choose two is going to be equal to five factorial over two factorial times five minus two factorial. Five minus two factorial, so this is five factorial over two factorial times three factorial. And this is going to be equal to five times four times three times two. I could write times one, but that doesn't really do anything for us. And then two factorial is just going to be two. And then the three factorial is three times two. I could write times one, but once again it doesn't do anything for us.