Look at this sequence from top to bottom. What is the next number in the sequence?
1
11
21
1211
111221
312211

A man says, "Brothers and sisters, have I none, but that man's father is my father's son." Who is that man?

What three numbers, none of which is zero, give the same result whether they’re added or multiplied?

There is one four-digit whole number n, such that the last four digits of n2 are the original number n

Solve the following series:
AZ, GT, MN, __, YB

I am a five-letter word and comprises two different vowels and three same consonants. I am so strong that I can spoil your entire work.

Can you find out who am I?

Which tank will fill first?

A four-digit number (not beginning with 0) can be represented by ABCD. There is one number such that ABCD=A^B*C^D, where A^B means A raised to the B power. Can you find it?

A sea diver is a real show-off. He showed everyone that he can hold his breath underwater for 15 minutes.

I went to the diver and told him that I can be underwater for double the time i.e 30 minutes.
He responded that he will give me 100$ if I would be able to do it. I won 100$.

What did I do?

Replace the question mark with the number below given a simple math problem.