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.
Sum{k=0..8}((8 choose k) * ((20!)/(20-k)!)/((75!)/(75-8)!) *((55!)/(55-8+k)!))
Natural Language
Math Input
Extended Keyboard
Examples
Upload
Random