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

What has many keys but can’t open a single lock?

Can you place six X (crosses) in below board without making three in a row in any way ?

Why is a river so rich ?

You are given four tennis balls and asked to arrange those balls in a manner that the distance between each one of them is exactly equal. How will you do it?

John has played 50 ODI's and his average is 50. How many runs should he score in his 51st ODI, so that his average score jumps to 51?

What is red and smells like blue paint?

What is in seasons, seconds, centuries and minutes but not in decades, years or days?

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

The day after tomorrow will be three days before Tuesday. Can you find out what is today?