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(n*(C(25,4)*C(35,n+2)/C(60,n+6)),n=1..32)
Natural Language
Math Input
Extended Keyboard
Examples
Upload
Random