## Gold box problem

There are ‘n’ gold boxes placed in a row, each having different number of gold coins.
2 players play a game, where the motive is to collect the maximum number of gold coins. Each player can see how many coins are present in each box, but can get a box from either end only, on his turn.
Design a strategy such that Player1 wins (Assuming both players play smartly)

Source: Amazon Interview

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## Remainder Problem

Find the sum of the remainders obtained when a number n is divided by 9 and 7 successively, if n is the smallest number that leaves respective remainders of 4, 6 and 9 when divided successively by 13, 11 and 15.

Source: www.time4education.com

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## Duck and Fox

A duck is swimming at the center of a circle-shaped lake. A fox is waiting at the shore, not able to swim, willing to eat the duck. It may move around the whole lake with a speed four times faster than the duck can swim. Can the duck always reach the shore without being eaten by the fox?

Source: Raphael Reischuk Riddles

## 2 Goats and 1 Car

You are on a game show and there are three doors. The presenter tells you that behind one of doors there is a car and behind the other two are goats. If you pick the car you win it. After you have picked a door the presenter opens a different door with a goat behind it, he then gives you the chance to change what door you open. What should you do?

Hint: It is not 1/2 as you would first think.

## Find the Number

Find the smallest number with the given properties

When I divide it by 2, the remainder is 1.
When I divide it by 3, the remainder is 2.
When I divide it by 4, the remainder is 3.
When I divide it by 5, the remainder is 4.
When I divide it by 6, the remainder is 5.
When I divide it by 7, the remainder is 6.
When I divide it by 8, the remainder is 7.
When I divide it by 9, the remainder is 8.
When I divide it by 10, the remainder is 9.

## The Dream Job

You are one of the 125 candidates that have been shortlisted to appear for an interview for a job in the company Amgon that pays five lakhs per month. Mr. Donny, a representative of Amgon is in the interviewing panel and he is responsible to select only one candidate for the job. He gives each candidate the same task in which he gives three dice each to every candidate. No marking of any kind has been done on any of the six faces of the dice. He tells them to write one letter each on all the faces of the three dice so that the top faces of the dice can show first three letters of all the months in the year. Can you complete the task and get the job?

Source: www.testfunda.com

## One Cord

You are given one cord that burns exactly one hour, not necessarily with constant speed.
How should you light the cord in order to determine a time interval of 15 minutes?
(Hint: solve the Two Cord puzzle first.)

Source: Raphael Reischuk

## Two Cords

You are given two cords that both burn exactly one hour, not necessarily with constant speed.
How should you light the cords in order to determine a time interval of exactly 15 minutes?

Source: Raphael Reischuk

## Number of ordered Pairs

Let S be a set of n consecutive natural numbers.
How to find the number of ordered pairs (A,B), where A and B are subsets of S and A is a proper subset of B?

For Example:
Let the set S = {1, 2, 3, 4, 5, 6, 7, 8}.
Find the number of ordered pairs (A, B), where A and B are subsets of S and A is a proper subset of B.

Source: www.testfunda.com

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## Candy Game

A group of students are sitting in a circle with the teacher in the center. They all have an even number of candies (not necessarily equal). When the teacher blows a whistle, each student passes half his candies to the student on his left. Then the students who have an odd number of candies obtain an extra candy from the teacher.

Show that after a finite number of whistles, all students have the same number of candies.

Source: www.puzzletweeter.com

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