Fred’s Packing Job

Fred was almost done packing for the day, with five packages left. Unfortunately, Fred dropped the labels and had no idea which label went to which package. What is the probability that Fred managed to correctly label exactly four of the five packages?

Zero. If Fred had correctly labeled four packages, the fifth label would belong to the fifth package and all packages would be correctly labeled. Therefore it is impossible to mislabel exactly four packages.

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Three Letter Word Completion

What three letter word can complete the below words?

B___
D___
M___ET
P___ING
SH___

Ark, which produces: bark, dark, market, parking, shark.

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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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A Big Pizza Pie

To get the most pizza, should you order two 12″ pizzas or one 18″ pie?

One 18″, with ~255 sumptuous square inches. Two 12″ pizzas would only give you ~226 square inches.

Note: The area of a circle is = πr2.

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Rope Around The Earth

If a piece of rope was tightly wrapped around the earth and you added 3 feet to its length, how high could you uniformly raise it from the earth’s surface?

Just short of 6 inches.

Thanks to Nigel Coldwell for this one.

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Rotating Coins Around Coins

You have two coins of equal size on a table, situated end to end vertically. If you roll the top coin around the bottom coin until it returns to its original position, how many times will it have rotated?

Twice. See this video for more details.

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BERETT ELTA NATH RENEV

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

BERETT ELTA NATH RENEV

Better Late Than Never

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Bank Wait Times

Suppose a small bank has one teller and customer transactions take 10 minutes on average. With 5.8 customers arriving per hour, what is the expected wait time? What would it be if you added a second teller?

With one teller, customers will wait nearly five hours on average. But adding a second teller makes the wait go down to 3 minutes.

Thanks to John D. Cook for this one.

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The Sheep’s Will

A farmer dies leaving a will dividing his flock of nineteen sheep with the following ratios:

Half to his oldest son, a quarter to the middle son and one fifth to his youngest son.

Without cutting any sheep up, how did the executor of the will fulfill the farmer’s wishes?

The executor went to the neighbouring farm and asked to borrow a sheep for a few minutes. Then he returned to the sons and said, “Half of the (now) twenty sheep is 10. A quarter of the twenty sheep is 5. A fifth of the twenty sheep is 4. 10 + 5 + 4 = 19. Then the executor took the borrowed 20th sheep back to the neighbour.

Thanks to Annette for sending this in.

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Ages Of Myself and My Brother

My current age, is the age of my 14 year-old brother plus one third of my age. How old will I be when my brother is twice his current age?

I will be 35. I am currently 21.

x = my current age

x = 14 + x/3
3x = 42 + x
2x = 42
x = 21 (so 14 years later, I'll be 35)
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