Interview Question: The Card Game
A casino offers a card game using a normal deck of 52 cards.
The rules are:
1)You turn over two cards each time.
For each pair:
- If both are black, they go to the dealer’s pile
- If both are red, they go to your pile
- if one black and one red, they are discarded.
2) The process is repeated until you two go through all 52 cards.
3) If you have more cards in your pile, you win $100; otherwise (including ties) you get nothing.
The casino allows you to negotiate the price you want to pay for the game. How much would you be willing to pay to play this game?
Strategy and Approach to Answering a Problem Solving Interview Question
If you get asked a problem solving question in an interview, remember that they are NOT looking for the RIGHT answer. They are evaluating the approach you use to think out and solve the problem. A strong candidate demonstrates the following:
- Evaluates and understand the scope of the problem
- Communicates assumptions
- Demonstrates quantitative analytical skills
- Answers the question that has been asked. You’d be surprised how many candidates get lost in the analysis and solve for a different question than what was asked.
How to answer this problem solving question
This problem sounds tougher than it really is. The easiest method is to understand a normal deck of cards has 52 cards (even number) and it has 26 red and 26 black (both equal and even).
So, you and the dealer will always have the same number of cards in your piles. Why? Because each pair of discarded cards have one black card and one red card, so equal number of red and black cards are discarded. As a result, the number of red cards left for you and the number of black cards left for the dealer are always the same.
The dealer always wins (remember ties, dealer wins). So you should not pay $0 to play the game.
Note: For this problem solving job interview question, there is an actual logical answer, however the interviewer will want to evaluate your thinking process. In answering the interview question, the lead up to your answer will be just as important as the actual answer itself.
For more problem solving, brain teasers, riddles, puzzles, logic job interview questions, please check our out Problem Solving Interview Section.
List of Problem Solving Interview Questions Used by Top Technology (e.g., Google, Microsoft) or Investment Banking Firms (e.g., Goldman Sachs)
- 100 Prisoners and a Light Bulb Interview Question
- 5 Pirates and 100 Gold Coins Interview Question
- Birthday Problem Interview Question
- Bridge Crossing Interview Question
- Burning Rope Interview Question
- Card Game Interview Question
- Crossing the River Interview Question
- Dog Show Interview Question
- Equal Halves of Rectangular Birthday Cake Interview Question
- Estimate the market demand in gallons for skim milk consumed in the U.S. in a given year.
- How many golf balls can you fit in a school bus?
- How many street lamps are there in Manhattan?
- How many times a day does a clock’s hands overlap?
- How Many Zeros in 100 Factorial (100!)?
- How much would you charge to wash all the windows in New York City?
- In a country, in which every family wants a boy
- Rising Tide Interview Question
- The Fermi Problem – How many Piano Tuners are there in Chicago?
- The Heaviest Ball Interview Question
- The Monty Hall Interview Question
- The Race Interview Question
- Tiger and Sheep Interview Question
- Why are manhole covers round?