Two Three Four Fifteen

What is the missing number?

2 3 4 15 12
3 4 5 28 20
4 5 6 45 30
5 6 7 66 42
6 7 8 ?? 56

91. To get the number in the fourth column, you add the numbers in column 1 and 2, then multiply by the number in column 2. f(n,m) = (n + m) * m
For example, f(2,3) = (2 + 3) * 3 = 15. Thus f(6,7) = (6 + 7) * 7 = 91

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LEWL GUNEB SI FLAH ENDO

Rearrange the letters of each word in this phrase to form a well-known saying.

LEWL GUNEB SI FLAH ENDO

Well begun is half done.

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The Yolk of the Egg

Which is correct to say, “The yolk of the egg are white?” or “The yolk of the egg is white?”

Neither. Yolks are yellow.

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First One, Then I Seem None

First I am one, then I seem none,
In death I birth new life.
What’s raised exceeds me,
For on bent knee,
I add to a world that’s rife.

What am I?

A seed. One seed turns into a plant or tree and seemingly disappears. When a plant dies, the seeds can be harvested to create new plants. From a single seed, hundreds more are created, vastly exceeding the original. Gardeners care for plants on bent knee and each new plant helps make the air fresher.

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Goes With a Car

What goes with a car, comes with a car, is of no use to a car, but the car can’t move without it?

Noise. The engine is usually the main culprit, but even electric cars make some noise from the tires on the road.

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Add Two To Eleven To Get One

When can you add two to eleven and get one as the correct answer?

When you add two hours to eleven o’clock to get one o’clock.

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A Perfect Counterfeit

A man can make perfect counterfeit bills. They look exactly like real ones, they’re made of exactly the same materials, made the same way, everything. So perfect, one could pretty much call them real bills. One day he successfully makes a perfect copy of another bill. However, he gets caught when he tries to use the copy. How is this possible?

As a counterfeiter, he had lots of counterfeit bills around and he accidentally used one of them as his original. So he made a perfect copy of a counterfeit bill.

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Special Strengths

What’s special about the word “strengths”?

It has a record nine letters but only one vowel, and it’s one of the longest one-syllable words in English.

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Rebellious Randall

You’re waiting to board your flight at the airport with 99 other passengers, each with an assigned seat. All but one of the passengers will gladly sit in their designated seat. The only exception is Randall, a scoundrel who refuses to follow the rules. When he boards, he will choose a random, unoccupied seat.

If a rule-following passenger finds someone in their spot, they will choose another one at a random from the remaining unoccupied seats.

What is the probability that the last person to board the plane will sit in their proper seat?

The randomness stops as soon as someone else sits in Randall’s assigned seat. The chances of this happening range from 1 out of 99 to 1 out of 1 (when only one seat remains).

Thus, the probability of the last person sitting in their own seat can be calculated as 1/99 plus the sum of 2 to 98 of the formula 1 / n × (n + 1), which works out to 0.5, or 50%.

So there’s a 50% chance the last passenger will sit in their own seat thanks to Randall for screwing up order and procedure when boarding an aircraft.

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A Lady’s Delight

Lovely and round,
I shine with pale light,
Grown in the darkness,
A lady’s delight.

What am I?

A pearl. They’re formed in clams, which are of course dark.

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