Loses Its Head Every Morning

What loses its head every morning only to get it back every night?

A pillow.

Posted in Riddles

A Corny Question

A merchant has 21 sacks of grain: 7 full, 7 half-full and 7 empty. He wants to divide them equally among his three sons. How can he do this, without transferring any grain between sacks, so each son has the same quantity of grain and number of sacks?

We know each son must end up with 7 sacks and 3.5 sacks of grain, since (7 sacks + 7 half sacks) / 3 = 3.5 sacks each.
There are two solutions.

Solution 1
Son 1: 3 full, 1 half-full and 3 empty.
Son 2: 3 full, 1 half-full and 3 empty.
Son 3: 1 full, 5 half-full and 1 empty.

Solution 2
Son 1: 2 full, 3 half-full and 2 empty.
Son 2: 2 full, 3 half-full and 2 empty.
Son 3: 3 full, 1 half-full and 3 empty.

Posted in Brain Teasers

How to Save Gas

If you could chose to increase the average fuel economy of a car, which of these would save the most fuel?

1. 10mpg -> 12mpg
2. 12mpg -> 15mpg
3. 15mpg -> 20mpg
4. 20mpg -> 30mpg
5. 30mpg -> 60mpg

It turns out they all save the same amount of fuel.

If you travel 100 miles:

100 / 10 = 10 gallons used
100 / 12 = 8 1/3 gallons used

10 – 8 1/3 = 1 2/3 gallons saved

100 / 30 = 3 1/3 gallons used
100 / 60 = 1 2/3 gallons used

3 1/3 – 1 2/3 = 1 2/3 gallons saved

Posted in Brain Teasers

Part Of The Bird

The part of the bird
that is not in the sky,
which can swim in the ocean
and always stay dry.

What is it?

The bird’s shadow.

Posted in Riddles

What is the center of gravity?

What is the center of gravity?

V. The letter ‘v’ is the center of the word gravity.

Posted in Riddles

Take Away All My Letters

Take away my first letter and I remain the same. Take away my last letter and I remain unchanged. Remove all my letters and I’m still me.

What am I?

A mail carrier. Letters in this sense are envelopes rather than the letters of the alphabet.

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

Asleep, Parts, Ideals Trianagrams

Rearrange the letters of the first word to form a new one, then rearrange the letters of the new word to form a third.

ASLEEP _ _ _ _ _ _ _ _ _ _ _ _
PARTS _ _ _ _ _ _ _ _ _ _
IDEALS _ _ _ _ _ _ _ _ _ _ _ _

1. ASLEEP, PLEASE, ELAPSE
2. PARTS, TRAPS, STRAP (TARPS or SPRAT also work)
3. IDEALS, SAILED, LADIES

Posted in Brain Teasers

I Cannot Speak

I cannot speak but I have great knowledge,
I’m not a tree but I have leaves.
I have hinges but I am neither a door nor a window.

What am I?

A book.

Posted in Riddles
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What is the Five Digit Number?

What 5-digit number satisfies the following requirements?

1. No zeroes
2. First two digits are the same
3. Fourth digit is twice the first
4. Last digit is twice the third
5. Sum of all digits is 18

33264.

There are several ways of solving this. One way is to represent each spot with a letter, A – E.

Then you have these equations:

A = B
D = 2 * A
E = 2 * C
A + B + C + D + E = 18

By simplifying, you get:

4 * A + 3 * C = 18

Plug in values for A and C to find that A = 3 C = 2.

Posted in Brain Teasers