Prove that the below maths equation is true.

8 + 8 = 91

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?

An infinite number of mathematicians are standing behind a bar. The first asks the barman for half a pint of beer, the second for a quarter pint, the third an eighth, and so on. How many pints of beer will the barman need to fulfill all mathematicians' wishes?

What is the fewest number of coins that would be required in order to make sure each and every coin touches exactly three other coins?

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?

Complete the series by replacing "?" with the correct number.

ST ND RD TH '?'

Below the four parts have been reorganised. The four partitions are exactly the same in both arrangements. Why is there a hole?

81 x 9 = 801. What must you do to make the this equation true?

A man and a dog were going down the street. The man rode, yet walked. What was the dog’s name?

Which flower has two lips?