I Can Be Long or Short

I can be long, or I can be short.
I can be grown, and I can be bought.
I can be painted, or left bare.
I can be round, or square.
What am I?

A fingernail.

Posted in Riddles

The Bookworm

A bookworm eats from the first page of an encyclopedia to the last page in a straight line. The encyclopedia consists of ten 1000-page volumes and is sitting on a bookshelf in the usual order. Not counting covers, title pages, etc., how many pages does the bookworm eat through?

        __                             __
      B|  |                           |  |F
      A|1 |...........................|10|R
      C|  |                           |  |O
      K|  |                           |  |N
       |__|                           |__|T
      -------------------------------------

On a book shelf the first page of the first volume is on the “inside”, so the bookworm eats only through the cover of the first volume, then 8 times 1000 pages of Volumes 2 – 9, then through the cover to the 1st page of Vol 10 for a total of 8,000 pages.

Note: The question asks how many pages, not how many sheets of paper.

Posted in Brain Teasers

The Pattern of Numbers

These series follow a pattern.
2 4 8
1 17 476
65 20987 3571890

This series does not follow the pattern
18 79 45

What is the pattern?

The numbers must be in ascending order. This can be a fun one to have people work out in person, as they test out three-number series and you can tell them whether or not they satisfy the pattern.

Thanks to Patrick for sending this in and thanks to this video from Veritasium for inspiring Patrick.

Posted in Brain Teasers

At Least One is a Boy

A couple has two children. At least one of them is a boy. Assuming the probability of having a boy or girl is 50%, what is the probability that both children are boys?

If you answered 1/2, you’re not without comrades, but the generally accepted answer by statisticians (though not without debate) is 1/3. This is because there are four possible combinations: boy-boy, boy-girl, girl-boy and girl-girl. Since we are told one of the children is a boy (but we don’t know if it’s the first or second child), we can rule out the girl-girl combination, leaving three remaining options. Only one out of 3 is boy-boy, so we get a 1/3 chance.

This is a well-known problem known as the Boy or Girl paradox. The other variation is this brain teaser.

Posted in Brain Teasers

Round, Yet Flat As a Board

Round she is, yet flat as a board
Altar of the Lupine Lords.
Jewel on black velvet, pearl in the sea
Unchanged but ever changing, eternally.

The moon.

Posted in Riddles

A Long Bicycle Ride

Hester goes out for an afternoon bicycle ride. She rides for one hour at five miles an hour, then three hours at four miles an hour and finally two hours at seven miles an hour. How many miles did she ride in total?

31 miles.

1 hour at 5 mph = 5 miles
3 hours at 4 mph = 12 miles
2 hours at 7 mph = 14 miles

5 + 12 + 14 = 31 miles

Posted in Brain Teasers

I Prevent Escape

I prevent escape or intrusion,
Yet I also preserve and protect,

Thieves use me to get money,
From me they can often collect.

I’m the practice of a sport, but not on the lawn,
Your friends may get upset when I’m sat upon.

What am I?

Fence. Fences keep ne’er-do-wells out and protect people inside. A fence is a person who buys stolen goods to later resell them for a profit. Those who fence practice the sport of fencing. En garde! And people don’t like it when you sit on the fence in a heated debate. (Believe me, I speak from experience)

Posted in Riddles
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All In White, A Fossil

All in white, a fossil,
fresh snow, a loan, the sky,
But just what am I?

A bride (something old, something new, something borrowed, something blue).

Posted in Riddles
Tagged with

Complete This GPPAP Series

What are the next four letters in this series?

GPPAP KTGAMTC WTBCOTP ????

GPRA – Georgie Porgie ran away.

Here’s the whole nursery rhyme:

Georgie Porgie, pudding, and pie,
Kissed the girls, and made them cry.
When the boys came out to play,
Georgie Porgie ran away.

Posted in Brain Teasers

How Can Four Be Half of Five?

How can the number 4 be half of FIVE?

Beginning with FIVE, take away the F and E (half of the letters), leaving IV, which is the Roman numeral for four.

Posted in Brain Teasers