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

An Abandoned Aquarium

There is an abandoned aquarium in an empty house. The aquarium has three large fish and three small fish. But after a week, one large fish and two small fish die.

How many remain in the aquarium?

Six, since no one is there to remove the 3 dead fish.

Posted in Brain Teasers

Fix This Roman Numeral Equation

This Roman numeral equation is wrong, but you can fix it without changing any of the elements of the equation. How is this possible?

I + XI = X

Look at it upside down. Instead of changing the equation, you can change your perspective.

This is from Dan Brown’s novel, Origin.

Posted in Brain Teasers

Take Away All My Letters

Take away my first letter,
Take away my second letter,
Take away all my letters,
and I remain the same.

What am I?

A mail carrier. Even when there aren’t any letters left to deliver, they’re job is still the mail carrier.

Posted in Riddles
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A Black Dog Sleeping

A black dog is sleeping in the middle of a black road that has no streetlights and there is no moon. A car coming down the road with its lights off steers around the dog. How did the driver know the dog was there?

It was daytime.

Posted in Riddles

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.

Posted in Brain Teasers

I Have Wings But Cannot Fly

I have wings but cannot fly.
I can do the twist but can’t move around.
People enjoy relaxing in my company.

What am I?

A ceiling fan.

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The Japanese IQ Test

Supposedly this is given as a test in Japan. I have no idea if that’s accurate.

There are 8 people who have to cross the river on a raft.

1. Policeman
2. Thief
3. Father
4. Boy 1
5. Boy 2
6. Mother
7. Girl 1
8. Girl 2

The rules are:

Only two people can cross at a time.
Only the adults can operate the raft.
The father can’t be with the girls unless the mother is there.
The mother can’t be with the boys unless the father is there.
The thief can’t remain with anyone unless the policeman is present.

How do you get them all across?

Here’s how I did it in 17 steps. Can you do it faster? Let me know in the comments.

1. Policeman (P)
2. Thief (T)
3. Father (F)
4. Boy 1 (B1)
5. Boy 2 (B2)
6. Mother (M)
7. Girl 1 (G1)
8. Girl 2 (G2)

1. P, T →
2. ← P

3. P, B1 →
4. ← P T

5. F, B2 →
6. ← F

7. F, M →
8. ← M

9. P, T →
10. ← F

11. M, F →
12. ← M

13. M, G1 →
14. ← P T

15. P, G2 →
16. ← P

17. P, T →

Posted in Brain Teasers

Its Own Past Tense

What common verb becomes its own past tense by rearranging its letters?

Eat (ate).

Posted in Riddles

Only Hides in the Unwound

What can be seen but never found that only hides in the unwound?

Relaxation. You can see when someone is relaxing, but no one can remain completely relaxed forever. You can relax more easily as you learn to unwind.

Posted in Riddles