You see a boat filled with people, yet there isn’t a single person on board. How is that possible?

Can you count the number of triangles inside a triangle?

What mathematical symbol can be put between 5 and 9, to get a number bigger than 5 and smaller than 9?

The square root of number 121 is "11". What is the square root of the number "12345678987654321."?

our enemy challenges you to play Russian Roulette with a 6-cylinder pistol (meaning it has room for 6 bullets). He puts 2 bullets into the gun in consecutive slots, and leaves the next four slots blank. He spins the barrel and hands you the gun. You point the gun at yourself and pull the trigger. It doesn't go off. Your enemy tells you that you need to pull the trigger one more time, and that you can choose to either spin the barrel at random, or not, before pulling the trigger again. Spinning the barrel will position the barrel in a random position.

Assuming you'd like to live, should you spin the barrel or not before pulling the trigger again?

In case you were starting to feel confident, this one was meant for third graders in Vietnam. The answer is 66, but we don't blame you for scratching your head about how they got there.

How many times do a clock's hands overlap in a day ?

What's the next in the series?

H, Be, F, S, Mn, Kr, In, Gd, Tl, ?

A tree doubled in height each year until it reached its maximum height over the course of ten years. How many years did it take for the tree to reach half its maximum height?

What are the next two letters in the following series and why?
W A T N T L I T F S _ _

*Hint: Check Puzzle Title