It is always ahead of me yet I can never see it. What is it?

What word is identified by the below rebus?

Your Your Your Your Your
Your Your Your Your Your

Can you count the number of quadrilaterals in the picture below?

The square root of number 121 is "11". What is the square root of the number "12345678987654321."?

What can you catch but never throw?

There are people and strange monkeys on this island, and you can not tell who is who (Edit: until you understand what they said - see below). They speak either only the truth or only lies.
Who are the following two guys?
A: B is a lying monkey. I am human.
B: A is telling the truth.

I shave every day, but my beard stays the same. What am I?

When a clock is observed, the hour hand is at a minute mark and the minutes hand is six minutes ahead of it.

When the clock is observed again after some time, the hour hand is precisely on a different minute mark and the minute hand is seven minutes ahead of it.

Can you calculate how much time has elapsed between the two observations?

What makes this number unique: 8,549,176,320?

There are 2 sand hourglasses.

The small one can measure 5 hours and the large one can measure 7 hours.

How can we measure 16 hours with 2 sand hourglasses running together ?