Tech companies are notorious for testing applicants' thinking skills with difficult interview questions. Although interview puzzles are less common these days--with Google demphasizing or doing away them--if you're going for a job in Silicon Valley or just want to check out some interview brainteasers, here are examples of challenging interview questions.
Business Insider Australia rounded up 11 tough interview questions posted on Glassdoor from employees, former employees, or former interviewees of Google, Microsoft, and Dropbox. They also post some suggested answers.
Some of them are fairly easy logic problems, like Google's "How many basketballs can you fit in this room?" Estimate the volume of the room and the space the average basketball would take up based on its diameter to calculate. There are clever answers to even the obvious questions, though, such as using a deflated basketball for the calculation.
- You have a cake. How many straight cuts do you need to divide the cake into 8 equal pieces? (Microsoft) - It might depend on the shape or if you want to make the least number of cuts to get the pieces.
- You work on the 60th floor of 100 story building. You walk into your office and find a bomb sitting on your desk. It reads 90 seconds and is counting down. What do you do? (Dropbox) - I'd say throw it out a window, but not knowing bomb logistics, am not sure if that's the right answer.
- How many people are using Facebook in San Francisco at 2:30pm on a Friday? (Google) - Estimate the number of people in SF, the percent of them that use Facebook, and then fudge some numbers based on the percent of people you'd think would be using Facebook based on that can't-wait-for-the-weekend time period.
As you can see, none of these questions have much connection with specific knowledge that matters in a job position at one of these companies (unless Dropbox regularly has ticking bombs in its offices). They're meant to have you demonstrate how you think, so more important than the answer you come up with is how you reason through the problem. In any interview--whether for a major tech company or an unknown startup--show them how you how you whittle down a problem to come up with a logical solution.
See the other 9 questions on Business Insider's slideshow.