Q: It’s karaoke night. The crowd chants your name. Your son of choice is … ?
A: “Sweet Caroline” by Neil Diamond
Q: Will you sing a few bars right now?
A: No. I’m no good.
Q: What’s another thing you suck at?
Q: What’s your favorite magic trick?
A: Anything with cards.
Q: Would you ever let someone saw you in half?
A: I did. I let a magician saw my head off.
Q: Did he let you saw his head off afterward?
A: No. I don’t think anyone trusts me to do that.
Q: If you could have dinner tonight with any one person, who would it be?
A: Either Albert Einstein or Elvis Presley.
Q: Um, we said “one person.”
A: OK, Albert Presley.
Q: What food grosses you out?
A: Squid. I used it for bait once when I was fishing. It stinks so bad.
Q: I what way are you a big nerd?
A: I’m a huge math nerd.
Q: OK—what’s the largest possible number you can write with two digits?
A: That’s a trick question. It would be nine to the ninth power.
Q: That’s right! Did anyone help you with that?
A: (Laughs) No. I have one for you. You have 12 gold balls all the same size, but one of them either weighs a little more or a little less than the other 11. Using a scale only three times, how do you figure out which ball is different?
Q: That’s tough. Will we be able to figure that out before this interview’s over?
Q: Will you tell us the answer?
Q: Gee, thanks. We hope your wife makes squid casserole tonight.
We put Parnevik’s brainteaser to Boise State University associate professor of business statistics Lyman Gallup, who solved it with little fuss. Click to the next page to see the answer … There are two keys to solving this problem: You must be able to identify the balls in order to keep track of previous weighings, and by the third and final weighing you must be down to at most three balls.
Randomly create three groups of four balls. Weigh two groups of four against each other. If they weigh the same, see step 2. If not, see step 9.
You now know that the odd ball is in the final (untested) group of four, and that the eight you put on the scale are standard.
Weigh any three of the four untested balls against any three standard balls. If the two groups weigh the same, see step 4. If the previously untested balls are heavier than standard balls, see step 5; if lighter, see step 7.
You know the final, untested ball is the odd ball. Weigh it against any standard ball to determine if it’s heavy or light. Pat yourself on the back.
You have learned that the odd ball is heavy. Take two of the three balls from the heavy group and weigh them against each other. See step 6.
Whichever side of the scale goes down holds the odd, heavy ball. If neither does, the third ball is heavy.
You have learned that the odd ball is light. Take two of the three balls from the light group and weigh them against each other. See step 8.
Whichever side of the scale goes up holds the odd, light ball. If neither does, the third ball is light.
The scale has tipped, so you know that the odd ball is in this original group of eight. It could be on the light side of the scale, among the four “potentially light” balls, or it could be on the heavy side of the scale, among the four “potentially heavy” balls.
Place two “potentially heavy” balls and one “potentially light” ball on either side of the scale. If they weigh the same, see step 11; if not, see step 12.
Weigh the two remaining “potentially light” balls against each other. Whichever goes up is the odd, light ball.
One side of the scale has gone down, indicating that the odd ball is one of the two “potentially heavy” ones on that side of the scale or the “potentially light” one on the other side.
Weigh the two “potentially heavy” balls against each other. If one side goes down, you know that that side contains the odd, heavy ball. If they weigh the same, the odd ball is the one remaining, and it’s light.