This One Stumped Einstein

by Stephen Noble

Years ago I ran across this brain teaser in of all places Integra. According to the article, which seemed credible enough to me, someone gave Einstein two brain teasers. Einstein solved one, but the other stumped him. Answers were not included in the article. Even if a person can not solve it - you're in good company - obviously it only takes arithmetic.

Here goes:

An old car in ill repair travels one mile up a hill, gets to the top of the hill, and travels one mile down the back side of the hill. If this old car in ill repair averages 15 mph going up the hill, how fast does it have to travel down the back side of the hill to average 30 mph for the whole two mile trip?

This one stumped Einstein, but it did not stump me. So, I can unequivocally state ... I'm smarter than Einstein! That was a joke - granted not much of a joke - but check it out anyway.

"Up and down the hill", and "old car in ill repair" are red herrings. The answer simply is: it can not be done. Think in terms of time: How long does it take a car to travel one mile at 15 mph? 4 minutes. How long does it take a car to travel two miles at 30 mph? 4 minutes...ergo...

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