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

Which word is least like the others? Third, fourth, fifth, sixth, seventh, eighth, ninth?

What breaks yet never falls, and what falls yet never breaks?

What animal walks on four legs in the morning, two legs during the day, and three legs in the evening?

Oedipus, the king of Thebes, figured out the answer to the riddle:

A 52% bias toss for head using the 51% tail bias coin was done to obtain a fair result.

Can you find how bias is the floor in this case?

Why do Chinese men eat more rice than Japanese men do ?

Can you find the missing piece of the Porsche?

How much will a 38° angle measure when looked at under a microscope that magnifies ten times?

Find three numbers such that

* When we multiply three numbers, we will get the prime numbers.
* The difference between the second and the first number is equal to the third and second.

I am a type of vehicle that has two wheels and is powered by humans. What am I?
Hint 1: You can ride me for exercise.
Hint 2: I am environment-friendly.