The Average of Three

There are three numbers. The first two are 2/3 and 3/4.

What does the third number have to be to make the average of all three be 2?

4 7/12

In order for the average of three numbers to be 2, they must all add up to 6. That gives you this equation:
2/3 + 3/4 + n = 6

Solve for n = 55/12, or 4 7/12.

Posted in Brain Teasers

One By One We Fall From Heaven

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?

Sands in an hourglass.

Posted in Riddles

Twice the Sum of Its Digits

What number is twice the sum of it’s digits?

18.

1 + 8 = 9
2 × 9 = 18

Posted in Brain Teasers

Mysterious Math

This problem can be solved by preschool children in five to ten minutes, by programmers in an hour and by people with higher education…well, check it yourself.

8809 = 6
7111 = 0
2172 = 0
6666 = 4
1111 = 0
3213 = 0
7662 = 2
9313 = 1
0000 = 4
2222 = 0
3333 = 0
5555 = 0
8193 = 3
8096 = 5
1012 = 1
7777 = 0
9999 = 4
7756 = 1
6855 = 3
9881 = 5
5531 = 0
2581 = ?

What is the missing number and why?

Two. The number is how many closed circles there are in the 4 digits. 0, 6 and 9 each have one, 8 has 2.

Posted in Brain Teasers

Embarrassing List

A woman gave a man a list of things she needed to buy at the store. The man gave the list back to the woman and she turned red with embarrassment. Why?

The man was a checkout clerk at the grocery store. The list was for items to get at a lingerie store.

Posted in Brain Teasers

Horses, Sleep and Dreams

What do horses, sleep and dreams have in common?

Nightmares.

Posted in Riddles

Word Value Of 52

If every letter of the alphabet is worth its numerical value (A=1, B=2, C=3), what’s a common 11-letter word whose letter values total only 52?

Abracadabra

Posted in Brain Teasers

Kneel In The Kayak

Kneel in the kayak grasping the boat, but don’t wrench the bullion or scowl at the chart. Behind the taped and sealed planter is a benevolent collier. The foxglove is in the bath.

Name the 19 creatures in the above sentence.

1. Eel
2. Yak
3. Asp
4. Boa
5. Wren
6. Bull
7. Lion
8. Cow
9. Owl
10. Hart
11. Hind
12. Ape
13. Seal
14. Ant
15. Vole
16. Collie
17. Fox
18. Ox
19. Bat

Posted in Brain Teasers

What One One One Represents

What do the following numerals represent?

11111121113122223222

The number of syllables in the numbers from one to twenty.

Posted in Brain Teasers

Something Everyone Needs

Everyone needs this, it’s great with an ‘r’ on the end but you’re sad when the first letter goes away.

What is it?

Love, lover, over

Posted in Riddles