Prove that the below maths equation is true.

8 + 8 = 91

What always comes into a house through the keyhole?

How many words can a pen with half refill write?

There was once a college that offered a class on probability applied to the real world. The class was relatively easy, but there was a catch. There were no homework assignments or tests, but there was a final exam that would have only one question on it. When everyone received the test paper it was a blank sheet of paper with a solitary question on it: 'What is the risk?'.Most students were able to pass, but only one student received 100% for the class! Even stranger was that he only wrote down one word!
What did he write?

Women do it once a year after they turn 19 but men get to do it only once in a lifetime. What is it?

When can we add 2 to 11 and get 1 as the correct answer?

Make a sentence consisting of three words that have the whole alphabet.

The answer I give is yes, but what I mean is no. What was the question?

The barber of Town shaves all men living in the town. No man living in the town is allowed to shave himself. The barber lives in that town. Who then shaves the barber of the town?

A boy was locked in a room by some robbers. All that is in the room is a piano, a calendar, and a bed. The room is locked from the outside. What does he eat, drink, and how does he escape and get out?