What is the word or phrase?

It's a test that will check your IQ.

Suppose you have one 11 minute hourglass and one 13 minute hourglass.

Can you measure exactly fifteen minutes using them ?

Sherlock Holmes was challenged to make a pre-drawn line smaller without erasing it. He did it in fractions of seconds. How?

People make me, save me, change me, raise me. What am I?

Analyze and find the missing item in the sequence:
16, 06, 68, 88, __, 98

How can a man go eight days without sleep?

I know a country, If you remove the last alphabet of its name, it will become a part of your body. Do you name it?

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 ?

What am I?

Here is a mathematical expression that also secretly tells a movie name. What movie is that?