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

An exterior architect is asked by a builder to plant seven trees in a manner that there are exactly six rows of trees in a straight line and each row has three trees in particular.

How will he do it?

You can see it everyday, But cannot touch it at will. What is it?

I’m tall when I’m young, and I’m short when I’m old. What am I?

The doctor prescribed you to take one pill from the bottle every half an hour. The bottle is now left with only three pills.

How long do you think you have before you run out of pills?

I have nine bottles of wine and one of the nine bottles is poisoned.
I need to find the poisoned bottle with two facts
(1) Poison is deadly, only a sip will cost death
(2) I have two mice to do so.

How should I do it?

I make a loud sound when I’m changing. When I do change, I get bigger but weigh less. What am I?

John has eleven friends. He has a bowl containing eleven apples. Now He wants to divide the eleven apples among his friends, in such a way that an apple should remain in his bowl.
How can He do it?

What's the best place to go shopping in the ocean?

Replace the question mark with the correct number in the below-given picture?