Carpooling

Four cars are driving in the carpool lane. The first contains five men in business suits; the second has a man and three high school students; the third, a woman and her young daughter; and the last, a pregnant woman. Which car or cars do not belong in the carpool lane?

To answer this, one might first ask, "Which cars have the potential to prevent another car from having to be on the highway?" Are the businessmen carpooling? Probably. They might have driven separately.

Shuttling students around cannot be keeping cars off the highway if they are not old enough to drive yet, right? Doesn't matter. If the man is taking his son and two teammates to soccer practice, he may be keeping two other cars off the road.

But the mother has just the young girl. Which car is she taking off the highway? None. But you might consider it carpooling if Mom dropped Becky off at ballet on her way to work instead of asking Dad to make a special trip.

In each of the examples above, the possibility exists that a car is being kept off the road. The potential is there; there's just no way to be certain.

As for the pregnant woman, how many cars can it take to transport a baby who has yet to be born? More than one? There's just no way.

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