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

Imagine you are in a room with no windows or doors. How will you get out?

Rectify the following equality 101 - 102 = 1 by moving just one digit.

What is the largest amount of money that you can possess in change and still if someone asks you for a dollar, you won't be able to give?

How many triangles are there on the puzzle below?

Which alphabet is a part of our body?

A research team went to a village somewhere between the jungles of Africa. Luckily for them, they reached the day when quite an interesting custom was to be performed. The custom was performed once a year as they confirmed and was performed in order to collect the taxes from every male of the region.

The taxes were to be paid in the form of grains. Everyone must pay pounds of grain equaling his respective age. This means a 20-year-old will have to pay 20 pounds of grain and a 30-year-old will pay 30 pounds of grain and so on.

The chief who collects the tax has 7 weights and a large 2-pan scale to weigh. But there is another custom that the chief can weigh only three of the seven weights.

Can you find out the weights of the seven weights? Also, what is the maximum age of the man that can be weighed for the payment of taxes?

I live in a bowl. I can swim. I have a tail. I also have fins and big eyes. What am I?

Which wheel of car does not rotate when you turn your car right?

How many pluses should we put between the digits of 987654321 to get a total of 99, and where?