City of Truths

Imagine you are on planet Trulie with only two inhabitants, one that always tells the truth, and the other that always lies. You reach a fork in the road with a sign to the City of Truths. Unfortunately, the road sign is down. Fortunately, a Trulian appears from nowhere. What question do you ask him to find the way to the City of Truth?

Adaptation of Doctor Spacemath from:
Fractals, Googols, and Other Mathematical Tales by Theoni Pappas

Fractals, Googols, and Other Mathematical Tales

by Theoni Pappas

Fractals, Googols, and Other Mathematical Tales by Theoni Pappas

Seven Socks

There are 7 red socks and 7 white socks in a drawer. If you must reach in the drawer blindfolded, what is the least number of socks you must pull out of the drawer so that you get either two reds or two whites?

Fractals, Googols, and Other Mathematical Tales by Theoni Pappas
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Sneak Preview

Would it be less expensive for you to take a friend to the movies three times, or three friends one time?

Fractals, Googols, and Other Mathematical Tales by Theoni Pappas
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The Snail Puzzle

A snail is climbing up a slippery 30 inch wall. It climbs 5 inches a minute, but then slides back 4 inches. How many minutes will it take to reach the top of the wall?

Fractals, Googols, and Other Mathematical Tales by Theoni Pappas