When Jack was six years old he hammered a nail into his favourite tree to mark his height. Ten years later at age sixteen, Jack returned to see how much higher the nail was. If the tree grew by five centimetres each year, how much higher would the nail be?

Why is the Hole below a Lock?

I have a head like a cat and feet like a cat, but I am not a cat. What am I?

You are stuck on an island where you have nothing. You find four pieces of paper somewhere on the island. What will be your strategy to escape from the island safely?

PS: No other resource is available to you on the island, neither can you build anything.

In The Image Below Which clock is the odd one out?

Until it is measured, not known. Yet how you miss it when it has gone. What is it?

It belongs to you, but other people use it more than you do. What is it?

How can you tell a raw egg from a hard-boiled egg?

Can you convert the number zero(0) into a positive number using just one mathematical operator ?

A certain street contains 100 buildings. They are numbered from 1 to 100. How many 9's are used in these numbers?