What is more useful when it is broken?

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?

A boy was at a carnival and went to a booth where a man said to the boy, "If I write your exact weight on this piece of paper then you have to give me $50, but if I cannot, I will pay you $50." The boy looked around and saw no scale so he agrees, thinking no matter what the carny writes he'll just say he weighs more or less. In the end the boy ended up paying the man $50. How did the man win the bet?

Which English verb becomes past tense just by rearranging the letters?

If I remove one from eleven it becomes Ten and if I remove one from nine also becomes Ten. How?

If it took eight men ten hours to build a wall, how long would it take four men to build it?

There were two grandmothers and their two granddaughters.
There were two husbands and their two wives.
There were two fathers and their two daughters.
There were two mothers and their two sons.
There were two maidens and their two mothers.
There were two sisters and their two brothers.
Yet there are only six, who are buried here,
All are born legitimate and relationships clear.
How can this happen?

They came out at night, without being called.
They lost at day, without being stolen.
Who are they?

Which five letter word can be added at the end of below word to form a
valid word?

> Pin
> Check
> Boiling
> View

If 1+9+8=1, what is 2+8+9?