#501 - Two Rectangles Two Matchsticks Puzzle
Can you move two matchsticks in the given picture in a manner that the resulting arrangement comes up with two rectangles?
See the image to find out how we did it. PS: Square is also a rectangle.
#502 - Missing Number Row Sequence
Can you find the missing number in the third row?
35 20 14
27 12 18
5 2 ?
The missing number is 20.
Here (left number / middle number) * 8 = right number
E.g. (35 / 20) * 8 = (7/4) * 8 = 7 x 2 = 14
You can follow the same to find out the remaining digit.
#503 - Confusing Probability Puzzle
You along with your friend are standing in front of two houses. Each of those houses inhabits a family with two children.
Your friend tells you the below two facts:
1) On your left is a family that has a boy who likes accounts but the other child loves science.
2) On the right is a family with a seven year old boy and a new born baby.
You ask him, "Does either of the family have a girl?"
To this he replies, "I am not quite sure. But can you guess that? If you are right, I will give you $200."
Which family do you think is likely to have a girl ?
1/2
In the house on the left, there are three possibilities:
Younger Older
Girl Boy
Boy Girl
Boy Boy
We cant have a girl-girl option because it has been mentioned that there is at least one boy in that house. Now all these outcomes are equally likely, and we have two events with girls, the chances of having a girl in the left house is 2/3.
In the house on the right, there are two possibilities because we already know that the older child is a boy:
Younger Older
Girl Boy
Boy Boy
Here the chances are 1/2.
Thus you must choose the house on the left for better chances at winning.
#504 - Knights Tour Chess Puzzle
In the picture, you can see a chess board. On the top left position, the K marks a knight. Now, can you move the knight in a manner that after 63 moves, the knight has been placed at all the squares exactly once excluding the starting square?
As you can see in the picture, the strategy used here is to cover the border first and then move to the inner squares.
#505 - Four Squares Matchsticks Puzzle
In the formation, you can see a few arranged matchsticks. Can you form three squares by moving just three matchsticks ?
The figures shows how to do it.
#506 - Who Is The Murderer Riddle
Role Action
Block Prevents the target player from acting
Redirect Change target player target.
Save Protects the target player from death.
Seer Sees all actions that occurred
Murderer Kills the target player
Following five players are playing:
Andy
Brian
Chris
Daniel
Fred
You are Andy the Seer and you saw the following things:
a) Brian was redirected to Chris.
b) Chris was blocked.
c) Daniel was killed.
Who is the murderer then?
The murderer is Fred.
Andy is the seer so exclude him.
Now, if Brian was murderer, then Chris should have been killed.
Now we know that Chris was blocked. Therefore he cannot be the murderer.
Daniel cant be the killer as he was killed himself.
This leaves with Fred.
#507 - Trick Story Puzzle
A man was telling some of his war stories to his grandchildren.
"When the World War I was on the verge of end, I was awarded for my bravery for I had saved a group of my men." He coughed and then added, "When we were fighting in northern France, an enemy soldier threw a grenade at us. Before it could explode, I picked it up and threw it away. For my act of bravery, right before the war ended, A General gave me a sword engraved with the words "Awarded for Display of Bravery and Heroism in World War 1"."
Hearing this, one of the grandson spoke up. "Grandpa, this is not a true story. It can"t be true!"
The truth is that it was not. How did the grand children know it?
The word "World War I" could not have been engraved on the sword. This is because the Second World War had not happened then and nobody knew that it will happen.
#508 - Famous Chess Board Puzzle
In a chess board, the queen piece can movie horizontally, vertically and diagonally freely. The picture represents the same.Can you place 8 queens on the board in a manner that none of the queens can attack each other?
See the image to find out how it can be done.
#509 - Hard Tricky Maths Trivia Question
Can you think of three numbers that gives a prime number as their product and also the difference between the second and first is equal to the difference between third and second?
The three numbers are: -3, -1 and 1.
Remember that we never asked for positive numbers.
#510 - Measure Time Interview Puzzle
There are two candles. Both will only burn exactly for an hour. How will you use these two candles to measure forty-five minutes?
Burn one candle from both the ends and simultaneously burn the other candle from just one end. In half an hour, the first candle would have been burnt fully and the second one would have been burnt half. Now light the other end of the second candle as well. In this way, the second candle will take only half the time (30/2 = 15) to burn fully.
Thus, you will have measured forty five minutes.