I have started a series of Youtube videos about rationality based on Steven Pinker’s book Rationality: What It Is, Why It Seems Scarce, Why It Matters (see my review of the book here). The videos explain what rationality is, how to use it correctly, and how it goes wrong.

See the playlist on my Youtube channel:

But first, how rational do you think you are? Try solving the below puzzles before watching the first video to see the solutions.

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A smartphone and a case cost $110 in total. The phone costs $100 more than the case. How much does the case cost?

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It takes 8 printers 8 minutes to print 8 brochures. How long would it take 24 printers to print 24 brochures?

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On a field there is a patch of weeds. Every day the patch doubles in size. It takes 30 days for the patch to cover the whole field. How long did it take for the patch to cover half the field?

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Consider the following problem: if a coin has a vowel on one side, then it has an even number on the other; which coins do you have to turn over to determine whether the rule has been violated?

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The famous Monty Hall problem: you’re in a game show and there are three doors, one has a car behind it, the other two have goats; when you pick one, the host opens one of the other doors to show that it has a goat behind it; should you change your guess?

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Rate each possible situation based on how likely it is to occur with one of the following: less than 0.01%, 0.1%, 0.5%, 1%, 2%, 5%, 10%, 25%, and 50% or more

1. 1. Saudi Arabia develops a nuclear weapon

   2. Nicolas Maduro resigns as president of Venezuela

   3. Russia has a female president

   4. The world suffers a new and more lethal strain of Covid-19

   5. Vladimir Putin is constitutionally prevented from running for another term as president of Russia and his wife takes his place on the ballot, allowing him to run the country from the sidelines

   6. Massive strikes and riots force Nicolas Maduro to resign as president of Venezuela

   7. A respiratory virus jumps from bats to humans in China and starts a new and even more lethal pandemic than Covid-19

   8. After Iran develops a nuclear weapon and tests it in an underground explosion, Saudi Arabia develops its own nuclear weapon in response