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[(12 choose k)(.25)^k(.75)^{12-k},k=0,2]
Sum[(12 choose k)(.25)^k(.75)^{12-k},k=0,2]
Natural Language
Math Input
Extended Keyboard
Examples
Upload
Random