In a jar there are 19 red jelly beans and 10 green jelly beans. In how many ways can you pick 4 red jelly beans and 4 green jelly beans? In a jar there are 19 red jelly beans and 10 green jelly beans. In how many ways can you pick 4 red jelly beans and 4 green jelly beans?

There are ${19 \choose 4}$ ways to pick 4 red jelly beans and $ {10 \choose 4}$ ways to pick 4 green jelly beans. Hence,

$${19 \choose 4}{10 \choose 4} = 813960.$$