# Seven Puzzles for the Seventh Month

The Old Bridge

Four people with one flashlight between them have to cross a rickety two-person capacity bridge in the next 17 minutes before a hurricane destroys it: Alice (who takes one minute to cross), Bill (two minutes), Cassie (five minutes) and Dave (10 minutes). It's pitch black, so anyone crossing needs the flashlight. How do they do it?

Gender Gap

In Ruritania, each couple stops having children if, and only if, they have a female baby. After many generations, what will the sex ratio in this country be? (a) Significantly more males than females; (b) Significantly more females than males; (c) Approximately 1:1

Assume: no multiple births; equal probability of a birth being male or female; life expectancy is the same for males and females.

Yin and Yang

Bisect (into equal areas) both the yin and the yang with one straight line.

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Four Cards

Each of four cards has a letter on one side and a number on the other.

Which cards must be turned over in order to check if the statement "Every card with a D on one side has a 3 on the other" is true?

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Harry S Truman

What does the "S" stand for?

Percentages

One hundred percent divided by 10 percent = (a) 0.1 percent; (b) 1 percent; (c) 10 percent; (d) 100 percent; (e) 1,000 percent.

Circles

The sum of the yellow areas is (a) less than; (b) equal to; (c) more than the sum of the blue areas.

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Bonus Question!

What do Ellis Bell, Ann Landers, Robert Galbraith, Anne Rice and George Orwell have in common, literary-wise?

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#### Barry Evans

Bio:
Barry Evans lives in Old Town Eureka with his girlfriend (and wife) Louisa Rogers, several kayaks and bikes, and a stuffed gorilla named “Nameless.” A recovering civil engineer, he is the author of two McGraw-Hill popular science books and has taught science and history. His Field Notes anthologies are available... more

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