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

There’s a one-story house in which everything is yellow. Yellow walls, yellow doors, yellow furniture. What colour are the stairs?

Irene killed hundreds of people mercilessly and yet the police were not able to put her behind the bars. Why?

An express train takes 3 seconds to enter the tunnel which is 1 km long.
If it is travelling at 120 km an hour, how long will it take to pass completely through the tunnel?

Many have heard it, but nobody has ever seen it, and it will not speak back until spoken to. What is it?

Complete the table series riddle by finding the number that can replace "??".

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

Consider all the numbers between 1 and 1 million. Among all these numbers, there is something very special about the number 8 and the number 2202. What is it?

A shepherd had 18 sheep, out of which, all but ten died.

Can you tell us how many sheep was he left with?

How many runs at maximum can a batsman score in a normal one-day match? Consider the fact that the conditions are ideal and there are no No Balls, no Wide Balls and no Extras in that match.