Can you find the key in the picture below?

In a university, a professor gave a set of three problems to the three brilliant students of his class. See the image for the questions.

Take 9 from 6, 10 from 9, 50 from 40, and leave 6.

How Come ??

Which word does the below Plexor means ?

In the below-given picture of a pretty girl, there is something wrong. Can you find out what it is?

What does this rebus riddle mean?

What is a word made up of 4 letters, yet is also made up of 3. Sometimes is written with 9 letters, and then with 4. Rarely consists of 6, and never is written with 5.

How can you take 2 from 5 and leave 4?

A Child was born in Lahore, Pakistan.

Still child is not a Pakistani citizen.why ?

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