Logic Problems Puzzles 1 : Donkey Puzzle
Difficulty ★★★☆☆ Popularity ★★★★★ A donkey travels the exact same distance daily.
strangely 2 of his legs travels 40 kilometers and the remaining two travels 41 kilometers.
Obviously 2 donkey legs cannot be a 1km ahead of the other 2.
The donkey is perfectly normal. So how come this be true ?
Solution:
The donkey is moving in circular path and hence outside legs travels more distance than inner legs
==============================================Logic Problems Puzzles 2 : Classic Logical Interview Puzzle
Difficulty ★★★☆☆ Popularity ★★★★★ I have two rectangular wires.
Both of them have property that when i light the fire from one end , it will take 60 minutes to get completely burn.
However they do not burn at consistent speed (i.e it might be possible 1st 20% burn in 50 minutes and 80% can burn in 10 minutes).
So how could i measure 45 minutes ?
Solution:
Steps:
A) burn 1st wire from both end and 2nd wire from one end
B) After 30 minutes(when 1st wire gets completely burned out) , burn the second wire from 2nd end as well
C) when 2nd run completely gets burned , you know its 45 minutes.
==============================================Logic Problems Puzzles 3 : Prison Break Riddle
Difficulty ★★★☆☆ Popularity ★★★★★ Two prisoners 'Lincoln Burrows' and 'Michael Scofield' are locked in a cell.
There is open window approx 30 feet above the ground of the cell.
They are never able to reach there.
Then they plan to escape by a tunnel and they start digging out.
After digging for more than 20 days, Scofield comes with the different plan and they escaped.
what was the plan ?
Solution:
They use the dirt and bricks from the tunnel and stand on it then one on top of the other.
==============================================Logic Problems Puzzles 4 : Monty Hall Problem Puzzle
Difficulty ★★★☆☆ Popularity ★★★★★ The host of a game show, offers the guest a choice of three doors. Behind one is a expensive car, but behind the other two are goats.
After you have chosen one door, he reveals one of the other two doors behind which is a goat (he wouldn't reveal a car).
Now he gives you the chance to switch to the other unrevealed door or stay at your initial choice. You will then get what is behind that door.
You cannot hear the goats from behind the doors, or in any way know which door has the prize.
Should you stay, or switch, or doesn't it matter?
Solution:
You better switch!
Your first choice has a 1/3 chance of having the car, and that does not change.
The other two doors HAD a combined chance of 2/3, but now a Goat has ben revealed behind one, all the 2/3 chance is with the other door.
==============================================Logic Problems Puzzles 5 : No Uninvited Guest Puzzle
Difficulty ★★★☆☆ Popularity ★★★★★ Queen Elizabeth organized a royal party.
To Avoid uninvited guest royal family set a password.
Wayne (an uninvited person) plan to enter the party. He stand nearby the door.
First guest comes, the security person said 'twelve' and guest replied with six.
Second guest comes , the security person said 'six' and guest replied with 'three'.
Wayne thought is enough and he walked to the entry point. The security person said 'eight' , Wayne replied smilingly 'four'.
He was immediately thrown out of the party.
why ?
Solution:
'five'
password is not half , rather the sum of digit.
==============================================Logic Problems Puzzles 6 : Popular Liar Truth Riddle
Difficulty ★★☆☆☆ Popularity ★★★★★ Suarez is a strange liar.
He lies on six days of the week, but on the seventh day he always tells the truth.
He made the following statements on three successive days:
Day 1: 'I lie on Monday and Tuesday.'
Day 2: 'Today, it's Thursday, Saturday, or Sunday.'
Day 3: 'I lie on Wednesday and Friday.'
On which day does Suarez tell the truth?
Solution:
Tuesday
We know that Suarez tells the truth on only a single day of the week. If the statement on day 1 is untrue, this means that he tells the truth on Monday or Tuesday. If the statement on day 3 is untrue, this means that he tells the truth on Wednesday or Friday. Since Suarez tells the truth on only one day, these statements cannot both be untrue. So, exactly one of these statements must be true, and the statement on day 2 must be untrue.
Assume that the statement on day 1 is true. Then the statement on day 3 must be untrue, from which follows that Suarez tells the truth on Wednesday or Friday. So, day 1 is a Wednesday or a Friday. Therefore, day 2 is a Thursday or a Saturday. However, this would imply that the statement on day 2 is true, which is impossible. From this we can conclude that the statement on day 1 must be untrue.
This means that Suarez told the truth on day 3 and that this day is a Monday or a Tuesday. So day 2 is a Sunday or a Monday. Because the statement on day 2 must be untrue, we can conclude that day 2 is a Monday.
So day 3 is a Tuesday. Therefore, the day on which Suarez tells the truth is Tuesday.
==============================================Logic Problems Puzzles 7 : Most Famous Maths Puzzle
Difficulty ★★★☆☆ Popularity ★★★★★ I can prove why 1 = 2
* Lets say y = x
* Multiply through by x xy = x2
* Subtract y2 from each side xy - y2 = x2 - y2
* Factor each side y(x-y) = (x+y)(x-y)
* Divide both sides by (x-y) y = x+y
* Divide both sides by y y/y = x/y + y/y
* And so... 1 = x/y + 1
* Since x=y, x/y = 1 1 = 1 + 1
* And so... 1 = 2
How is this possible ?
Solution:
Step 5 is invalid, because we are dividing by (x-y), and since x=y, we are thus dividing by 0. This is an invalid mathematical operation (division by 0), and so by not following basic mathematical rules
==============================================Logic Problems Puzzles 8 : Logic Thinking Puzzle
Difficulty ★★★☆☆ Popularity ★★★★★ At a restaurant downtown, Mr. Red, Mr. Blue, and Mr. White meet for lunch. Under their coats they are wearing either a red, blue, or white shirt.Mr. Blue says, 'Hey, did you notice we are all wearing different colored shirts from our names?' The man wearing the white shirt says, 'Wow, Mr. Blue, that's right!'
Can you tell who is wearing what color shirt?
Solution:
Blue could only be wearing white or red and we know that there is already someone else wearing the white shirt so Mr. Blue could only be wearing the red shirt.
Mr. White could have only been wearing a blue or a red shirt, and red is already taken, so Mr. White is wearing a blue shirt.
Mr. Red now has to be wearing a white shirt.
==============================================Logic Problems Puzzles 9 : Fun Math Puzzle
Difficulty ★★★☆☆ Popularity ★★★★★ Baseball bat and ball cost $50. If the bat cost $49 more than the ball, what is the cost of each
Solution:
bat $49.50, ball $0.50
==============================================Logic Problems Puzzles 10 : Logic Interview Question
Difficulty ★★★★☆ Popularity ★★★★★ The first box has two white balls. The second box has two black balls. The third box has a white and a black ball.
Boxes are labeled but all labels are wrong!
You are allowed to open one box, pick one ball at random, see its color and put it back into the box, without seeing the color of the other ball.
How many such operations are necessary to correctly label the boxes?
Solution:
Just One!
Because we know all labels are wrong.
So the BW box must be either BB or WW. Selecting one ball from BW will let you know which.
And the other two boxes can then be worked out logically.
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