In our last post, we discussed how to answer the types of job interview questions where you cannot really prepare an answer. Rather, you can simply prepare how you will answer. These logic puzzles and brain teasers are a tough bunch, but if you attack the problems the right way, you will easily win over your interviewer, even if you get it wrong.
Today we are going to look at quantitative brain teasers. These questions require you to do math in order to support your answer. There are several keys to answering these questions correctly:
- Don’t rush through it.
- Take your time to come up with a logical answer.
- Tell the interviewer your thought process.
- Don’t act like it was unfair for the interviewer to not give you all the information necessary to get an accurate answer.
It is difficult to explain without using an example, so consider the following question made up by Everyday Interview Tips for the purposes of this article.
Sample Quantitative Interview Question
You are a window washer on the empire state building. You can only carry five buckets of water with you on your platform at any given time, otherwise the platform will lose balance. You can wash approximately 20 windows with those 5 buckets before the water gets too dirty and you need to go back down to bottom floor to refill them. How many times will you have to refill the buckets before you have completed the entire building?
Now, you can construct an actual answer for this if you know exactly how many windows there are on the empire state building, but chances are you don’t, nor does your interviewer. They are not expecting you to necessarily get the answer right. What they want to see is how you attack the problem. Ask for a pencil and paper and do some math, based on what you can estimate, then once you think you’re on the right track and have found an answer that suits you, explain it.
“Well, without knowing exactly the number of windows or floors of the Empire State building, I think a safe estimate is about 100 floors, with an average of 10 windows per side. There are four sides to the building, so that would be 40 windows per floor, or 4,000 windows for the entire building. If I can only wash 20 windows, that would be 4,000 divided by 20, or 200. Of course, you also said ‘refill’ implying that the water was already filled, so I would have to go down to refill the buckets 199 times.”
This is how you should answer the question. Technically the answer is wrong. There are 6,500 windows on the empire state building, and the building is 102 floors. It doesn’t matter. What is important is that you used sound logic to come up with your answer, and explained that logic to the interviewer. This is a correct job interview answer for a quantitative brain teaser, even though the answer is incorrect.
Take Away Interview Tips
- Give each answer thought and logic.
- Explain that logic to your interviewer.
- Remain composed and professional – don’t panic about getting the answer wrong.
- “I’m not good at math” is not an appropriate answer.
- If you hear this question at your job interview, your interviewer stole it from us.