What is at the end of a rainbow?

You are presented with three boxes. One of them has a red ball inside and the other two have a black ball inside each of them. You are asked to pick up the one with red ball and you pick one. Now, one of the other boxes is opened and it is found to have a black ball.

You are presented with a chance to change your box with the one that is left closed. Will you change your box? Why or why not?

What has lots of eyes, but can’t see?

They are the five precious gems of an everyday sort and all can be found on a Tennis Court. Who are they?

Alpha is Beta's sister.

Gamma is a Beta mother.

Delta is Gamma's father.

Tango is Delta's mother.

Then,

How is Alpha related to Delta?

Why is the Hole below a Lock?

Find the Next Number in the Sequence

2 9 3 1 8 4 3 6 5 7 ?

Why do we preferably have round manhole covers and not square ones?

There are two candles. Both will only burn exactly for an hour. How will you use these two candles to measure forty-five minutes?

Why is 6 afraid of 7?