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

The teacher told the student that if he told a lie then he will be expelled from school and if he told the truth then he still is expelled from school.

What can a student say to prevent his being expelled from school?

There was a competition where the contestants had to hold something. At the end of the event, the winner was a person who had no hands or feet. What was it that the contestants had to hold?

Below, you will find the mathematical proof that 10 equals 9.99999?. But is that possible or there is something wrong about it? Can you find the error?

x = 9.999999...
10x = 99.999999...
10x - x = 90
9x = 90
x = 10

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

You know three triplets: Frank John and Wayne (need to return your money). Frank always tells the truth while John and Wayne always lie. You meet one of them on the road and can ask him a three-word question.
Which question, will you ask?

Solve the rebus riddle in the picture below.

In particular commonwealth games, a female participant won silver and gold medals for a single event.

How can this be possible?

Out of four images which one is the odd one out?

Which word does the below Plexor means ?