(sum k=1..4 of ((-1)^(k+1)*binomial(4,k)*binomial(24-2k,10-2k)))/(binomial(24,10))

Uh oh! Wolfram|Alpha doesn't run without JavaScript.

Please enable JavaScript. If you don't know how, you can find instructionshere.Once you've done that, refresh this page to start using Wolfram|Alpha.