Puzzles, riddles, logical
questions, and lateral thinking questions are important part of any selection
process for a job interview.
You
can check how good you are by answering these top 10 interview puzzles.
1.
Ant and Triangle Problem
Three ants are sitting at
the three corners of an equilateral triangle. Each ant starts randomly picks a
direction and starts to move along the edge of the triangle. What is the
probability that none of the ants collide?
2.
Crossing the Bridge Puzzle
Four people need to cross
a rickety bridge at night. Unfortunately, they have only one torch and the
bridge is too dangerous to cross without one. The bridge is only strong enough
to support two people at a time. Not all people take the same time to cross the
bridge. Times for each person: 1 min, 2 mins, 7 mins and 10 mins. What is the
shortest time needed for all four of them to cross the bridge?
3.
Burning Rope Problem
A man has two ropes of
varying thickness (Those two ropes are not identical, they aren't the same
density nor the same length nor the same width). Each rope burns in 60 minutes.
He actually wants to measure 45 mins. How can he measure 45 mins using only
these two ropes.
He can't cut the one rope
in half because the ropes are non-homogeneous and he can't be sure how long it
will burn.
4.
Heaven’s Gate Probelm
You are standing before
two doors. One of the path leads to heaven and the other one leads to hell.
There are two guardians, one by each door. You know one of them always tells
the truth and the other always lies, but you don’t know who is the honest one and
who is the liar. You can only ask one question to one of them in order to find
the way to heaven. What is the question?
5.
10 Coins Puzzle
You are blindfolded and
10 coins are place in front of you on table. You are allowed to touch the
coins, but can’t tell which way up they are by feel. You are told that there
are 5 coins head up, and 5 coins tails up but not which ones are which. How do
you make two piles of coins each with the same number of heads up? You can flip
the coins any number of times.
6.
King and Wind Bottles Puzzle
A bad king has a cellar
of 1000 bottles of delightful and very expensive wine. A neighboring queen
plots to kill the bad king and sends a servant to poison the wine. Fortunately
(or say unfortunately) the bad king’s guards catch the servant after he has
only poisoned one bottle. Alas, the guards don’t know which bottle but know
that the poison is so strong that even if diluted 100,000 times it would still
kill the king. Furthermore, it takes one month to have an effect. The bad king
decides he will get some of the prisoners in his vast dungeons to drink the
wine. Being a clever bad king he knows he needs to murder no more than 10
prisoners – believing he can fob off such a low death rate – and will still be
able to drink the rest of the wine (999 bottles) at his anniversary party in 5
weeks time. Explain what is in mind of the king, how will he be able to do so ?
7.
Mislabeled Jar Puzzle
You have 3 jars that are
all mislabeled. One jar contains Apple, another contains Oranges and the third
jar contains a mixture of both Apple and Oranges.
You are allowed to pick
as many fruits as you want from each jar to fix the labels on the jars. What is
the minimum number of fruits that you have to pick and from which jars to
correctly label them?
8.
Red and Blue marbles Puzzle
You have two jars, 50 red
marbles and 50 blue marbles. You need to place all the marbles into the jars
such that when you blindly pick one marble out of one jar, you maximize the
chances that it will be red. When picking, you’ll first randomly pick a jar,
and then randomly pick a marble out of that jar. You can arrange the marbles
however you like, but each marble must be in a jar.
9.
Gold Bar Problem
You've got someone
working for you for seven days and a gold bar to pay him. The gold bar is
segmented into seven connected pieces. You must give them a piece of gold at
the end of every day. What and where are the fewest number of cuts to the bar
of gold that will allow you to pay him 1/7th each day?
10.
100 Doors Puzzle
You have 100 doors in a
row that are all initially closed. you make 100 passes by the doors starting
with the first door every time. the first time through you visit every door and
toggle the door (if the door is closed, you open it, if its open, you close
it). the second time you only visit every 2nd door (door #2, #4, #6). the third
time, every 3rd door (door #3, #6, #9), ec, until you only visit the 100th
door. What state are the doors in after the last pass? Which are open which are
closed?
