Best Brain Breaking Questions

Last time we were in Paris.Mammu and I-Mammu fell in love with Eiffel tower.She began to insist that we carry the Eiffel tower to India. I tried to explain that such thing was impossible. But nothing would make her see reason. Finally I had to promise her that I would make an identical tower for her in our miniature.
In order to make an identical replica, I enquired the exact details of Eiffel tower. here are the details:
The Eiffel tower is 300 meters high and it is made up of steel and its weight was 8,000,000 kilograms. I have to decided to make a model with 1 kilogram of steel.
How high would my Eiffel tower be?

Every man or woman alive today had 2 parents, 4 grand-parents, 8 great grand-parents, 16 great-great grand parents, 32 great-great-great grand parents and so on.
Let us take the case of Ram. Two generations ago Ram had 2*2 or 4 ancestors. Three generations ago he had 2*2*2 or 8 ancestors. Four generations ago he had 2*2*2*2 or 16 ancestors.
Assuming that there are 20 years to a generation, can you tell 400 years back how many ancestors did Ram have?

I was shopping for vegetables in the New market. I saw to pumpkins of the same quality but with different sizes. One was bigger than the other. The circumference of the first pumpkin was 60 cm and the circumference of the other was 50 cm. I asked the vendor for the price. The bigger one was one and a half times more expensive than the smaller one. Which one do you think would have been a better buy

There are 150 members in my club. We decided to have a ping pong tournament. All the members cam forward to play the tournament. Every time a member loses a game, he is out of the tournament. There are no ties.
Can you tell how many games must be played in order to determine the champion?

Last winter I went to United kingdom. Travelling from London to Manchester, I had company of two middle-aged Englishmen who were seated opposite to me. Naturally we didn't speak to each other because we were not introduced to each other. But i heard what they were saying. Their conversation was like this,
"How old is Tracy, I wonder?"... one asked the other."Tracy!".....the other replied "Let me see - eighteen years ago she was three times as old as her son....but now she appears as she is only twice old as her son" said the former.

When i shopped in to the New market i had altogether Rs 140/- in purse. When i walked out I didn't have a single rupee. Instead i had a cloth, a pair of shoes and a handbag.
The cloth cost Rs 90/- more than the handbag, the cloth and the handbag cost Rs 120/- more than the pair of shoes.
How much is the cost of each item.

We have a brick of regular size. It weighs 4 kilograms. How much do you think is a smaller brick, four times smaller but made of the same material weigh?