The Honest and Dishonest Guards

You’re in a room with two doors. There’s a guard at each door. One door is the exit, but behind the other door is something that will kill you. You’re told that one guard always tells the truth and the other guard always lies. You don’t know which guard is which. You are allowed to ask one question to either of the guards to determine which door is the exit.

What question should you ask?

Ask either guard what door the other guard would say is the exit, then choose the opposite door.

If you ask the guard who always tells the truth, he knows the other guard would lie, so he’ll point you to the door leading to death. If you ask the guard who always lies, he knows the other guard would truthfully show you the exit, so he’ll lie and point you to the door leading to death.

An alternate solution is to ask a guard what they would answer if you were to ask them which door was the exit, then choose that door. The truthful guard will point to the correct exit, but the lying guard will too. Here’s why. If you asked him what door was the exit, he would normally lie and point to the death door, but you asked him what he would say if you asked what door was the exit, and in order to lie to that question, he will point you to the exit.

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

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

I A N Rebus

What does the following rebus represent?

I           A
      N
R           B

Scatterbrain.

Posted in Riddles
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Swallow

You can swallow me, but I can swallow you. What am I?

Water.

Posted in Riddles
Tagged with

The Pope Has It

The Pope has it but he does not use it. Your father has it but your mother uses it. Nuns do not need it. Arnold Schwarzenneger has a big one, Michael J. Fox’s is quite small. What is it?

A last name, also known as a surname.

Posted in Brain Teasers

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)
Posted in Brain Teasers

Midway Numbers

Select the number that is midway between the lowest number and the highest number.
Which number is midway between that number and the number that is nearest the highest number?

35  5 52 36 67
69  4 51 37 71
55 68  3 53 39

53.

37 is midway between 3 (the lowest number) and 71 (the highest number).
53 is midway between 37 and 69 (nearest to the highest number).

Posted in Brain Teasers

Walks on Graves at Night

This walks on graves at night yet in homes during the day,
Men are scared of it, women like it, children play with it,
It lives on dates and salt,
It is covered in hair,
Its name starts with ‘M’ and it is mentioned in the Quran.

What is it?

Moths.
Most species of moths are nocturnal, yet they are attracted to light and can be found in homes. Men, in the most generic sense, can be scared of moths (see Mottephobia) as well as the damage they can cause as pests to bee hives, grain, flour, trees and agriculture. Women like moths because of the silk they produce. Children frequently chase and play with moths. Moths are attracted to salt and love to eat rotting fruit (such as dates). Some species of moths are densely covered with tiny hairs and of course it starts with the letter ‘m’. Lastly, moths are mentioned in the Quran (101:4 (Asad) [It will occur] on the Day when men will be like moths swarming in confusion)

Posted in Riddles

On My Own I’m Twenty-Fourth

On my own I’m 24th,
Two of us and I’m 20,
Three of us and I’m 18.

What am I?

The letter X. It is the 24th letter of the alphabet, two Xs in Roman numerals equals twenty and triple x represents adult content, and adulthood is eighteen by law in most countries.

Posted in Riddles