Mind Teasers : Fake Coin Brain Teaser
In front of you, there are 9 coins. They all look absolutely identical,
but one of the coins is fake. However, you know that the fake coin is
lighter than the rest, and in front of you is a balance scale. What is
the least number of weightings you can use to find the counterfeit coin?
The answer is 2. First, divide the coins into 3 equal piles. Place a pile on each side of the scale, leaving the remaining pile of 3 coins off the scale. If the scale does not tip, you know that the 6 coins on the scale are legitimate, and the counterfeit is in the pile in front of you. If the scale does tip, you know the counterfeit is in the pile on the side of the scale that raised up. Either way, put the 6 legitimate coins aside. Having only 3 coins left, put a coin on each side of the scale, leaving the third in front of you. The same process of elimination will find the counterfeit coin.
Mind Teasers : Popular Logical Riddle
A mules travels the same distance daily.
I noticed that two of his legs travels 10km and the remaining two travels 12km.
Obviously two mules legs cannot be a 2km ahead of the other 2.
The mules is perfectly normal. So how come this be true ?
The mules is moving in circular path and hence outside legs travels more distance than inner legs.
Mind Teasers : Unique Brain Teaser
It takes ten minutes to fry a steak (five minutes for each side). You
are frying the steaks in a pan that can accommodate only two steaks at
one time. What is the least amount of time by which you can fry all the
three steaks you have?
After frying for five minutes, you can take out one steak and put the third one inside while turning the other one inside. After five more minutes, one steak is fried from both sides and you can take it out. Now put in the steak that we removed and turn the other one inside. After five more minutes, they both will also be fried from both sides.