Get ready with a paper and a pen in your hand before you start reading…!!!!!
1> Puzzle on digits.
Write down 0123456789(a 10-digit number) in a piece of paper. Now you have to write another 10 digit number below this such that
a. If you write a digit below some digit then you will have to use the digit written in second row as many number of times the number in first row.
Ex: Your answer will be something like this assume you have filled only 6th and 9th digits in second row.then
XXXX3XX2X .. You have fill remaining positions and use digits 5 and 9- 3times and 2 times respectively as you have written 3 below 5 and 2 below 9..
2> A thief and bread puzzle:
A thief goes to a bakery and he steals bread loaves. He takes the loaves 5 times and he follows a theory that he takes each time half of the left number of loaves and an half loaf.Now you have to find what is the number of loaves he stole from the bakery.
3> Balance Puzzle
Balance puzzles are very popular ones that are based on the balancing of similar-looking items, often coins, to determine which one is of a different value within a limited number of uses of the balance scales.
Well.. Let us try to solve some of them.
A> There are 9 coins which are similar but one is odd in its weight remaining 8 have same weight. Now you have to find that odd one. If you given a balance what is the minimum weighs needed to do find the odd coin?
B> Repeat the above problem with 1800 coins.
C> This one little more tricky.
You are given 9 coins as in A> but you are not told whether the odd coin weighs more or less. Now how many weighs you need to solve A.
Check out SOLUTIONS available.Password is KEY.
Many more will be coming here..Enjoy logical solving..:)
Update: Download this PDF for more puzzles and solution Interview Puzzles
4> Puzzle with weights:
You have a pan. you have to weight all the weights from 1 t0 40kgs(only integers) by using only a minimum weights i.e. you can add , subtract by placing weights on two sides of the pan.. What is the minimum number of wights you need?
we have three variants in this puzzle
A> Place only on one side and you can take out some weights placed before.
B> You can place weights on both sides of pan also can take out weight placed before
C> Place only on one side but not allowed to take out weights once placed in pan and can change the side on which weights placed before.
(Solve before looking for answer..)
A> In this case any weight has two options 1. placed on pan and 2. not on pan.So this series can be represented in binary 2^0 +2^1 +2^2 +2^3 +2^4….. so on..from this if we have to weigh all weights below X kg. we need all the terms in series below X .. Here 40 so we need 1,2,4,8,16,32 ..total 6 weights
B> In this case it follows gray code series of binary .please find out Binary to gray conversion details in this document.
.Also for more Binary-to-Gray code
C> In this case as we can place weights on both side it will have three possibilities 1. placed in pan 2. not placed in pan 3. placed in other side of pan so that we subtract some weight to get effectively required weight. 3^0,3^1, 3^2 ,3^3 …so on.. Similar to previous one to weigh X kg.s we need all weights below X from this series. 1,3,9,27 for 40kg.s