10 brain-straining Google interview questions

Google is known for its challenging interview questions – here are some of the toughest questions its IT candidates had to face.

By - March 24, 2016 Share on LinkedIn
Google Office

Google was ranked as the most attractive employer in South Africa in Universum’s recent 2016 Most Attractive Employer Awards.

To get a job at Google is not easy, though, as the company is renowned for its stringent interview process.

Google’s South African office said it is looking for people who are great at a lot of things, love big challenges, and welcome big changes.

This raises the question: What type of interview questions will candidates face when trying to land a job at Google?

Seattle job coach Lewis Lin published a list of questions from Google which his clients faced during the interview process – here are the tougher ones and their answers.

Why are manhole covers round?

Manhole cover

A round manhole cover cannot fall through its circular opening, whereas a square manhole cover could fall in if it were inserted diagonally.

A man pushed his car to a hotel and lost his fortune. What happened?

Pushing car

He was playing Monopoly. The car is his token, and when he arrives at the property with the hotel, he does not have enough money or property to pay the rent.

Explain the significance of “dead beef”?

Cow skin

0xDEADBEEF (“dead beef”) is used by IBM RS/6000 systems, Mac OS on 32-bit PowerPC processors, and the Commodore Amiga as a magic debug value.

What’s 2 to the power of 64?

Applied Mathematics

18,446,744,073,709,551,616 – it is read as eighteen quintillion, four hundred and forty-six quadrillion, seven hundred and forty-four trillion, seventy-three billion, seven hundred and nine million, five hundred and fifty-one thousand, six hundred and sixteen.

How much money do you think Google makes daily from Gmail ads?

Gmail logo

An explanation here.

How many golf balls can fit in a school bus?


Divide 2.5 cubic inches into 1.6 million cubic inches and you come up with 660,000 golf balls.

However, since there are seats in there taking up space and also since the spherical shape of a golf ball means there will be considerable empty space between them when stacked, round down to 500,000 golf balls.

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


If Seattle consists of 10,000 city blocks with 600 windows per block, and the window washer spends five minutes per window while being paid a rate of $20 per hour, the answer would be approximately $10 million.

How many times a day do a clock’s hands overlap?


The first time the minute and hour hands overlap, the minute hand would have completed 1 lap more than the hour hand. So we have T = T/12 + 1.

This implies that the first overlap happens after T = 12/11 hours (~1:05 am). Similarly, the second time they overlap, the minute hand would have completed two more laps than the hour hand. So for N overlaps, we have T = T/12 + N. Thus, the hands of a clock overlap 22 times a day.

How many piano tuners are there in the world?

Piano tuner

Given the average piano owner tunes his piano once a year: (50 weeks/year)×(5 days/week)×(8 hours/day)/(2 hours to tune a piano) = 1000 piano tunings per year per piano tuner. Now find the number of pianos in the world, and you are off to a good start.

What is the probability of breaking a stick into 3 pieces and forming a triangle?

Google Drive

If you break a stick at two points chosen uniformly, the probability of the three resulting sticks forming a triangle is 1/4.

More on Google

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Apple now using Google Cloud for some iCloud data

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