Can you place six X (crosses) in below board without making three in a row in any way ?

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

Can you count the number of triangles in the given figure?

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 ?

Why do we preferably have round manhole covers and not square ones?

A shepherd had 18 sheep, out of which, all but ten died.

Can you tell us how many sheep was he left with?

A prisoner is told: "If you tell a lie, we will hang you and if you tell the truth, we will shoot you." What did the prisoner say to save himself?

What has to be broken before you can use it?

Pronounced as one letter,
And written with three,
Two letters there are,
And two only in me.
I am double, I am single,
I am black blue and grey,
I am read from both ends,
And the same either way.

There are nine dots in the picture that has been attached with this question. Can you join all the dots by drawing four straight lines without picking up your pen?