[MSL]

A thread to post interesting puzzles, brain teasers,

logic problems and so on

I've decided to start a new thread in this omnilogical community and, concretely, to put it in the philosophy board.
 The main idea behind this thread is to post many good brainteasers, logical problems, puzzles...
 I welcome you!

[Non-SEO]

Playing Cards Trick

 The certain magician tells you he’s going to amaze you with an interesting trick. He then invites you to do the following:

            a) Open a brand-new deck of playing cards, place them face down on the table.
            b) Count off the top twenty cards, turn them face up, and insert them at random into the remainder of the deck.
            c) Shuffle the deck thoroughly.
            d) Count off the top twenty cards and hand them to him under the table.

  After a period of "magic" activity under the table, he places his pack of twenty cards next to yours of 32. He says, he has arranged that both packs now contain the same number of face-up cards. You count and... they do!!!

How did he do this trick?

ANSWER: Simply by turning over the whole pack of twenty cards. (This guarantees that both packs will contain the same number of face-up cards.)

[MSL]

A gender problem

In a fictional kingdom, boys and girls are born in strictly equal proportion. Determined to increase the proportion of men in the land, the king issues a decree: Any woman who bears a daughter is forbidden to have any further children. He reasons that some families will thus contain multiple sons but a single daughter. Years later the king is very confused to find that the kingdom still contains an equal number of boys and girls!

Why is that?

ANSWER: The first set of births after the king’s decree will be half girls and half boys. But so will every subsequent set. The number of births will diminish steadily, but this won’t affect the ratio of  girls to boys.

[Gay]

7 Letters

  Imagine this:
A woman has 7 letters:
The 1st 2 stand for a boy or a man.
The 1st 3 stand for a girl or a woman.
The 1st 4 are a brave boy or a brave man
And the 1st 6 are a narcotic.
But all of her letters together stand for a brave girl or a brave woman.
What is she?

ANSWER: Heroine.

[MSL]

2 bolts

  OK, let's think now about this one:
 Let's suppose that you have got 2 identical bolts. Hold each by its head, engage the threads together and revolve one about the other. Will this act pull the heads closer together or it will drive them farther apart?

ANSWER: Neither. In effect one bolt turns clockwise, the other anticlockwise at the same rate, so the distance between their heads will remain unchanged.

[Gay]

Russian roulette problem

  We’re playing Russian roulette for fun. The revolver has six chambers, all empty. I put bullets in two adjacent chambers, spin the cylinder, hold the gun to the target in the field, and pull the trigger. It clicks. Now it’s your turn. Before pulling the trigger, you can choose:
a) to spin the cylinder again
b) leave it as it is.
 Which is better for you?

ANSWER: It’s better not to spin it. Two of the six chambers are loaded, so my chance of winning was 4/6. But you know that the hammer fell on an empty chamber. Of the four empty chambers, only one is followed by a loaded one. So if you simply pull the trigger, you have a 3/4 chance of winning. That’s better than 4/6, so you’re better off not spinning the cylinder.

[MSL]

A water problem

  A tank of water has 2 holes of equal size. 1 is near the top and 1 is near the bottom. The top hole leads to a downspout, so that both holes actually discharge their water at exact the same level. If we ignore the friction, which hole produces the faster water flow?
Can you solve this?

 ANSWER: The water flows from both holes at the same rate.

[Gay]

Another one about water

 A scale balances a glass of water with a certain weight. If someone put his or her finger into the water and he or she is careful not to touch the glass, will it upset the balance?
 
 ANSWER: Yes. The water imparts an upward force on your finger as you immerse it, so you must exert a downward force to overcome it. That force is transferred to the glass and then to the scale, which sinks.

[Gay]

Smells like blue paint

  What is red and smells like blue paint?
 
 ANSWER:

Red paint.

Hehehe!!!

[MSL]

Bassoon-Train question

You want to take your one-piece bassoon^{(You may learn more about this here -- http://en.wikipedia.org/wiki/Bassoon)} on the train, but the bassoon is 1.7 meters long and the baggage man won’t take any item whose greatest dimension exceeds one meter. What can you do?

 ANSWER: The bassoon will fit diagonally in a cubical box ONE meter on a side.

[Non-SEO]

An interesting conundrum

  Let's imagine this... You have got 100 pounds of imaginary potatoes, which are 99% water by weight. You let them dehydrate until they’re 98% water. How much do they weigh now?

 ANSWER: Perhaps surprisingly, these imaginary potatoes now weigh 50 pounds. The sack of potatoes originally weighed 100 pounds, and 1 percent of its weight, or 1 pound, was non-water. If that 1 pound now makes up 2 percent of the total weight, then the total weight must be 50 pounds.

[Gay]

Foot size and performance in spelling bees

  There is a direct, positive correlation between foot size and performance in spelling bees(spelling tests). Can you explain this? 
 
  ANSWER:Usually, the larger the feet, the older the person.

[MSL]

Four

  Well, 4 hours ago, it was as long after 4 AM as it was before 4 PM the same day. What time is it right now?

 ANSWER: It's 2 PM. The halfway point between 4 AM and 4 PM is 10 AM, but that was 4 hours ago. Thus 10 AM + 4 hours = 2 PM.

[MSL]

A Peculiar Roman Numerals Equation

  If you still don't know about the Roman Numerals, you may learn about them here: http://en.wikipedia.org/wiki/Roman_numerals and now let's read this peculiar Roman numerals equation:

How would this equation be correct without changing it:

"XI + I = X" ?

 

ANSWER: Just turn it upside down.

[MSL]

How many times

How many times in 24 hours does a clock’s hands overlap?

ANSWER: 22 times.
AM: 12:00, 1:05, 2:11, 3:16, 4:22, 5:27, 6:33, 7:38, 8:44, 9:49, 10:55.
PM: 12:00, 1:05, 2:11, 3:16, 4:22, 5:27, 6:33, 7:38, 8:44, 9:49, 10:55.