Why Aeroplane windows are round?

If you drop me I’m sure to crack, but give me a smile and I’ll always smile back. What am I?

As you can see that fifteen matches have been used to form an arrangement. What you have to do is remove any six of them to make them ten.

what does the below rebus means?

I possess a head

I flaunt a tail

But I don't have mouth or legs

Can you find out who I am?

A prisoner is told: "If you tell a lie, we will hang you and if you tell the truth, we will shoot you." What did the prisoner say to save himself?

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

One absent-minded ancient philosopher forgot to wind up his only clock in the house. He had no radio, TV, telephone, internet, or any other means for telling time. So he travelled on foot to his friend's place a few miles down the straight desert road. He stayed at his friend's house for the night and when he came back home, he knew how to set his clock. How did he know?

Using eight eights and addition only, can you make 1000?

I throw two dice simultaneously.

What is the probability of getting a sum as 9 of the two numbers shown?