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

It is an eleven letter word.
The first, second, third and fourth letters form a banquet's name.
The fifth, sixth and seventh letters form a car's name.
The eighth, ninth, tenth and eleventh letters form a mode of transport.

Can you identify what word it is?

John can place six large boxes or nine small boxes into a carton.

Can you find out in how many cartons can he place sixty-six boxes in total?

There are people and strange monkeys on this island, and you can not tell who is who (Edit: until you understand what they said - see below). They speak either only the truth or only lies.
Who are the following two guys?
A: B is a lying monkey. I am human.
B: A is telling the truth.

What is full of holes but still holds water?

Can you find the missing number in the third row?
35 20 14
27 12 18
5 2 ?

Can you count the number of triangles in the given picture?

What is the coolest letter in the alphabet?

Four cars come to a four-way stop, each coming from a different direction. They can’t decide who got there first, so they all go forward at the same time. All 4 cars go, but none crash into each other. How is this possible?

Can you name an animal whose killing cannot be performed without spilling your own blood?