Answers (in order):
- Put three balls on each side of the scale. If the arms are equal, you know the heavy ball is one of the two remaining. If the arms are unequal, take the three balls on the heavier side, pick two and weigh them against each other.
- The hour hand will have moved one-fourth of an hour; therefore there will be 7.5 degrees between the two hands.
- Fill up the three-gallon container and pour it into the five-gallon container. Do it again — and there will be one gallon left in the three-gallon container. Empty the five, pour in the one, fill the three again and pour it into the five-gallon container — and you've got four.
- To get matching socks, you need to pick three — there are only two colors, after all.
- To find the way to Truthtown, simply ask the man, "Which way is your hometown?" Then go whichever way he points: if he's from Liartown, he'll point to Truthtown and if he's from Truthtown, well, you get it.
- Manhole covers are round so that they can't fall into the manhole.
- Obviously no one expects you to tell them the precise number of barbers in Chicago; they want to hear you go through a line of thinking. The variables you'll want to consider are the population of Chicago and the percentage that's male; the number of haircuts the average male has per year divided by the number of days in the year, taking into account the number of days per year barbershops are open; and the number of haircuts an average barber can give per day. By the way, there are 550 barber shops in Chicago; 6,273 active barbers in Illinois; with 66% of the state's population, Chicago has roughly 4,140 barbers.
- To get a job at NERA, calculate the price of your home using conventional valuation methods — but remember to throw in the value you attach to your memories for however long you've lived there.
- There is only one cube at the center of a Rubik's Cube.
- To get the guard to give you a cigarette (and this really is the preferred answer to this question), threaten to kill yourself by smashing your head against the wall of your cell. That gives you leverage with the guard — he'd be tied up doing paperwork about your suicide, so he'd miss weekend time with his family (it's Friday afternoon, remember?) — so he'll give you a cigarette.
A version of this article appeared in the November 1995 issue of Fast Company magazine.