xkcd.com has been running a weekly feature called "What If?" for a few months now, and as others have noticed, Erfworld's very own Rob Balder asked the second question addressed in the feature: "What if everyone who took the SAT guessed on every multiple-choice question? How many perfect scores would there be?"
What you may not know is that Rob appears also to have TWO other questions featured on the site! That's assuming that "Rob B" is short for "Rob Balder." Check them out!
SAT Guessing: http://what-if.xkcd.com/2/
Machine Gun Jetpack: http://what-if.xkcd.com/21/
Cost of Pennies: http://what-if.xkcd.com/22/
I'm pretty sure no other asker has been featured more than once, and here Rob has been on there three times already! It's a shame xkcd.com doesn't link to Erfworld; Randall seems like a fan of Rob's work!
