Brainteasers

$1.19. There are a few ways to think about this, but the easiest is to start with the largest coin – quarters – first and then work your way down. 4 quarters equals $1.00, so we clearly can’t do that – but 3 quarters are ok because that’s only $0.75. Next, we have dimes. Recall … Read more You have stacks of quarters, dimes, nickels and pennies (these represent $0.25, $0.10, $0.05 and $0.01, respectively, in the US monetary system for anyone international). There are an unlimited number of coins in each stack. You can take coins from a stack in any amount and in any order and place them in your hand. What is the greatest dollar value in coins you can have in your hands without being able to make change for a dollar?

142.5 degrees. If we just think of the clock hour hand at 1 and the minute hand at the 45 position (near 9 o’clock), that is 120 degrees since they are 4 “numbers” apart, and each number on the clock represents 30 degrees (360/12). However, recall that the hour hand has already moved by the … Read more What is the angle formed by the hands of the clock when it is 1:45?

Test the functionality of the calculator’s computing accuracy by evaluating whether inputs provide their expected outputs. Also, test the device’s basic system functions — like the power button, the clear function, and so on, to determine whether you’ll be facing system errors before you can compute anything. Depending on the position for which you’re interviewing, … Read more How would you test a calculator?

When you reach the end of the list you will come back to the beginning of the list (a circular list). Write the most efficient algorithm to find the minimum # in this list. Find any given # in the list. The numbers in the list are always increasing but you don’t know where the … Read more You are given a list of numbers…

A candiate for Quantitative Compensation Analyst should know that Google hired about 3,400 people in 2008. Figure 75%, or 2,550, of those hired were engineers and that, like Harvard, Google only accepted 3% of those who applied. 2,550 is 3% of 85,000.

The object of the game is to direct a frog to avoid cars while crossing a busy road. You may represent a road lane via an array. Generalize the solution for an N-lane road. “One approach is to write a recursive algorithm that determines when to “wait” or to “jump” to the next lane, depending … Read more Design an algorithm to play a game of Frogger and then code the solution…

Merge Sort for sorting. O(1,000,000,000,000 Log 1,000,000,000,000) – Average Case Scenario O(1,000,000,000,000 Log 1,000,000,000,000) – Worst Case Scenario I’d guess you can do 1 billion operations per second, thus 3000 seconds.

You have to write a function in which you pass the whole game and name of a player. The function will return whether the player has won the game or not. First you to decide which data structure you will use for the game. You need to tell the algorithm first and then need to … Read more You are given a game of Tic Tac Toe…

There’s no one answer to this. The interviewer wants to test the interviewee’s imagination and creativity with problem solving. We feel like reader “Dude” might impress a Google interview with this answer: Organize them according to types of clothes like a HASH and then organize each type into a 2-3-4-Tree or RedBlack Tree.

This is obviously an extremely vague question, and there isn’t really one correct answer. A good answer is one in which the interviewee demonstrates familiarity with the term “latency” and enough imagination to come up with an interesting problem with an interesting solution.