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

I have an apple tree , number of apple in this tree get doubles every week.

On 30th week , the tree gets completely filled with apples :-)



Can you tell me , on what week does my tree is half covered with apples ?

You have an empty wine bottle with a cork that has been secured at the top in a normal way. There is a metal ring inside the bottle that is suspended by a string.

How can you make the metal ring drop to the bottom if you are not allowed to touch anything - not the bottle, not the cork, not the thread and not the ring?

There are three boxes which are labeled as Rs100, Rs150, and Rs200. One box contains two notes of Rs. 50. The second box contains one note of Rs50 and one note of Rs100 The third box contains two Rs. 100 notes. All boxes are labeled incorrectly.

What is the minimum number of boxes you must check in order to label all boxes correctly?

If you had a pizza with crust thickness 'a' and radius 'z', what's the volume of the pizza?

Count the number of balls in picture below:

A wooden log balances equally on the scales when weighed with three-quarters of a pound and three-quarters of a wooden log.

Can you calculate the weight of the entire wooden log?

Most people think of me as money. But when they find me in the water, they won’t get any money out of me. What am I?

What begins with T, ends with T, and has T in it?

There's one "sport" in which neither the spectators nor the participants know the score or the leader until the contest ends.

What is it?