Count the number of lines in the image below ?

I have no doors but I have keys, I have no rooms but I have space, you can enter but you can’t leave! What am I?

Three friends decide to distribute the soda cans they had among them. When all of them had drunk four cans each, the total number of cans that remained was equal to the cans each one of them had after they had divided the cans.

Can you calculate the total number of cans before distribution?

In the image below, you can see two glasses and two matchsticks.You need to move four matchsticks in such a manner that the crosses come inside the glasses. Note: you cannot move the crossed.

A seven-year-old kid challenged his classmates that he can make the number one disappear by adding something to it.

How can he do that?

An American nightclub called 'The Coconut Grove' had a terrible fire in which over 400 people died. A simple design flaw in the building led to a high death toll. Subsequently, regulations were changed to ensure that all public buildings throughout the country eliminated this one detail, which proved deadly. What was it?

Find The Missing Number In the Sequence.
6 25 64 ? 32 1

You are playing a game with your friend Jack. There are digits from 1 to 9. You both will take turn erasing one digit and adding it to your score. The first one to score 15 points will win the game.

Would you want to play first or second?

PS: The sum should be exactly 15.

A word I know has six letters it contains, remove one letter and 12 remain. What is it?

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