10 

Two Trains 
20 

Odd Pills 
12 

Carpeting a Donut 
5 

Count The Bits 
6 

Partitioning a set 
4 

Don't Mate in One 
1 

Parodoxical Statements from Life 
The Monty Hall Problem
This can definitely be solved using Baye's Rule, but it may be easy to get lost in the math. The Carlton solution in the Show Solution box is definitely the easiest to understand. context 
Up and Down
With that logic, he could just carry the umbrella everyday :) context 
Crazy Google Interview Question
I've heard this solution before. This would assume you stay perfectly centered on the axis of rotation and can keep yourself in good balance. context 
Bit Pair Swap
I agree with ravi, your solution doesn't work. context 
3 Coins
Are you sure? How did you arrive at your answer? context 
Crazy Google Interview Question
Assuming it's a standard blender with two blades connected perpendicularly to the axis of rotation, I would just stand on the axis of rotation. I would rotate with the blades, but would probably live... context 
3 Coins
Nice! Solid explanation. context 
Parodoxical Statements from Life
TouchÃ©, although I assume the question is invariant to language changes. context 
Odd Pills
Woah, nice solution. Similar motivation to the solution I posted, but much cleaner once you work through it. context 
Odd Pills
The solution is explained in detail under "Show Solution", but the key idea is that you take different amounts of pills from each jar so you'll know exactly which jar has the pills with a different weight. For example, if jar 2 has the 9 gram pills and you picked 2 pills from jar 2, the total weight of the pills will be 2 grams less than the expected weight Expected weight of pills coming from jar 2: 2 x 10g = 20g Actual weight of pills coming from jar 2: 2 x 9g = 18g context 
Good luck at an interview with Google
I think you might have to take into account how tightly you can pack spherical balls into some volume. With 12,000 inches^3, you would only be able to fit 3,000 balls if they were all perfectly packed together. Check this out: Closepacking of equal spheres context 
Bug's Eye
Agreed. I think the same diagram without the red path would be ideal. context 
Psycho Killer
That too, the fact that she's scoping out dream guys at her mother's funeral is pretty messed up. context 
Good luck at an interview with Google
I think the question might be asking what the total cost of washing all windows in Seattle would be, with some assumed market rate for washing windows. Why bilingual advertisement? There's more than 2 languages in the world. Also, what if the advertisement doesn't reach all of the piano tuners worldwide? If it does reach everyone in the world, what if it is seen in a region that doesn't speak one of the two languages? context 
No if() Only abs()
Isn't that just 1/2? context 
All the King's Wine
+1 Michael. This same problem without a supporting story would just be ridiculous. context 
20
6
Odd Pills
Your pharmacist gives you 5 jars filled with pills. The pills contained in each jar have an identical appearance and size (i.e. if you mixed all of the pills you wouldn't be able to tell them apart).
...

Doable

5
Count The Bits
Write a function that counts the number of bits in an integer that are set to 1 that is linear in time complexity in the worst case, but sublinear on average.

Hard
