Uh oh! Wolfram|Alpha doesn't run without JavaScript.
Please enable JavaScript. If you don't know how, you can find instructions
here
.
Once you've done that, refresh this page to start using Wolfram|Alpha.
\frac{{30\choose k}{30\choose 4-k}}{{60\choose 4}} for k=0,1,2,3,4
Natural Language
Math Input
Extended Keyboard
Examples
Upload
Random