Can you name some countries which do not have the alphabet 'A' in them?

Imagine a box with two cogwheels, one big with 24 teeth and one small with 8 teeth. The big one is firmly attached to the center of the box which means it does not turn or move while the small one rotates around the big one.

How many times do you think that the smaller wheel will turn compared to the box when it turns once around the big one?

What is the centre of gravity?

How can you leave a room with two legs and return with six legs?

O_er_t_o_

Complete the missing letters of the given word.

Can you convert the number zero(0) into a positive number using just one mathematical operator ?

Replace the question mark with the correct number.

2 + 2= 4
3 + 3= 18
4 + 4= 48
5 + 5= ?

There are 2 people near the river and both of them want to get on the other side. The boat can only take one of them. But they got across.
How?

An equation has been laid down using a few matchsticks. However, as you can see, the equation is not correct. Can you correct the equation if you are allowed to add or remove 5 matchsticks?

He does not have any heart but still, He manages to live.
If you kill him, you will eventually die but yet you kill him.
He cannot run, who is He?