What has six faces, but does not wear makeup, has twenty-one eyes, but cannot see?

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

How many letters are in the alphabet?

Which statement is true out of the following?
One statement here is false.
Two statements here are false.
Three statements here are false.

John went to a parrot shop in Mexico, and the parrot owner told him that his parrot is so unique that he repeats everything he hears. John got excited and immediately bought the parrot. John went home and spoke many words, but the parrot does not repeat anything.
He went again to the parrot shop and complaint to the shopkeeper, but the shopkeeper never lied. Explain?

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

Using Only Five 5's and any mathematical operator make sum as 37

In the picture that is attached with this question, you can find a square which comprises of four little squares inside it. Consider this square to be made with matchsticks. You have to remove two matchsticks such that only two squares remain instead of five.How will you do it ?

I am never scared but became petrified and can’t live in a house but would die to make one. What am I?

A family is trapped in a jungle. There is a bridge which can lead them to safety. But at one time, the bridge can only allow two people to pass through. Also, all of them are afraid of the dark and thus, they can't go alone.

Father takes 1 minute to cross, the mother takes 2 minutes, the son takes 4 and the daughter takes 5 minutes. While crossing the time taken will be according to the slower one. How can they all reach the other side in the minimum possible time?