08.31.07
Silicon Valley interview questions?
This is not the first time I read news articles about tough questions interviewees were asked during an interview for top companies such as Google. My favorite one is “why are the sewer lids round in shape instead of square”?
I have always questioned about the effectiveness of those questions, especially from my “bad” experience. I once attended an interview from Microsoft, and the interview went very well at the beginning. Suddenly, I was asked if I were the product manager, how could I design a remote control for senior people.
My answer was: if I were the manager I would like to conduct a full survey of seniors first, and ask for what difficulties they have when they use a remote control. The manager was very disappointed with my answer, and he started lecturing me about what suggestions I should have give. He named a long list of features he think it would be “cool” for seniors. I did not want to argue during the interview, but all I had in my mind was: if I were the manager, I need to make sure the product addressing the need not just to be “cool”. The real question is: will seniors really spend hard earned dollars for a universal remote control? I believe simplicity is over functionality in this perticular case. Apparently my performance didn’t impress the manager and he cut short with my interview immediately. When I got home, I googled the interviewer’s name and surprisingly learned that he was actually the team lead for Outlook 97 and Outlook 2002. Any thoughts of that? 
Nonetheless, I still like to read and solve these interesting interview questions as brain teasers, but I deeply doubt the usefulness in an interview since if you cannot press the “hot button” you will be judged unfairly. On one hand it helps to pick up smart thinkers, on the other hand it filtered out deep thinker.
The question I read today is “how much money will you make if you clean all windows in Seattle”? The author has suggested the following answer:
assume 10000 buildings in Seattle; 600 windows per building; 5 mins per window; $20 per hour wage; the income will be $10 million
I think this answer is kinda boring, so I tried some other approaches:
(1) If I were granted a contract to clean all windows in Seattle, I would become a monopoly. So I can charge whatever price and maximize the economic rent as long as consumers can afford, which means I can make way more than $10 mil! More importantly, if I could subcontracted the work, I could make money sooner.
(2) Think about time value of money! Sure, you can finish all windows and make $10 mil. However, to finish all windows it took more than 57 years if I did it non-stop, 24X7. If I worked as normal, I could not even finish the work in my life. Therefore, this income stream becomes a “perpetuity”. Assume I worked 8 hours a day, $20 hours per hour, 200 days per year, my annual income would be $36,000 and assume my expected rate of return is 5%, the present value of my total income would be $36000/0.05 = $720,000, which is way less than $10 mil.
Things can get even more complicated if you combine the idea (1) and idea (2). Happy brain teasing!
