What is in seasons, seconds, centuries and minutes but not in decades, years or days?

What Does this text mean:

important=important

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.

A man wants to cross the pit of fire which is 25 feet in length and he has 2 planks(fire resistant) 19 feet in length. How can he cross the pit of fire alive?

Count the number of triangles in the below picture?

Solve the counting riddle by identifying the number of triangles in the given picture.

Suppose that you are trapped on the surface of a frozen lake. The surface is so smooth and ideal that there is no friction at all. You cant make any grip on the ice and no wind is blowing to help you out. You have just a mobile phone with you which has got no reception disabling you to call for help.

How will you plan your escape before you freeze to death on the frozen lake?

You see a mathematical expression in the picture. Can you think of a movie that this expression refers to?

My location can be determined by the below rebus.
So where am i ?

We have shown you a regular water barrel as below. Without using any measuring device can you check if the barrel is more than half-filled or less than half-filled?