How many gas stations are there in the US?

How might one answer this question? Start by estimating how many gas stations might be in a town of around 30,000 people, and then extrapolate for the U.S. population, which is about 314 million people. It turns out there are upwards of 117,000 gas stations in the U.S. According to the U.S. Census Bureau, in … Read more How many gas stations are there in the US?

How much should you charge to wash all the windows in Montana?

Remember that not all questions must have a complicated answer. Yes, this question is especially broad—but you could get around that by naming what you consider to be a fair price per window rather trying to figure out the number of windows in the area.

How many tennis balls can you fit into a limousine?

1,000? 10,000? 100,000? In these types of questions, the interviewer doesn’t necessarily want an exact number—he wants to make sure that you understand what’s being asked of you, and that you can set into motion a systematic and logical way to respond. So, just take a deep breath, and start thinking through the math. For … Read more How many tennis balls can you fit into a limousine?

Which of these pieces of information would be most useful in estimating the number of people who work in a 30-story building?

The number of cars in the parking lot. The number of people eating lunch in the cafeteria. The number of people on the 11th floor. Any one of these three are pretty inadequate without more data. If you can get information on whether the building’s suburban or urban, you can make a guess as to … Read more Which of these pieces of information would be most useful in estimating the number of people who work in a 30-story building?

How many piano tuners are there in the entire world?

A good answer would be “However many the market dictates. If pianos need tuning once a week, and it takes an hour to tune a piano and a piano tuner works 8 hours a day for 5 days a week 40 pianos need tuning each week. So one for every 40 pianos.” The classic Fermi … Read more How many piano tuners are there in the entire world?

A guide to paying taxes on bitcoin

Around the world, tax authorities have tried to bring forth regulations on bitcoins. The US Internal Revenue Service (IRS) and its counterparts from other countries are mostly on the same page when it comes to treatment of bitcoins. The IRS said that the bitcoin should be treated as an asset or an intangible property and … Read more A guide to paying taxes on bitcoin