Railroad Crossing, look out for the cars. Can you spell that, without any R's ?

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?

Two old friends, Jack and Jill, meet after a long time, and discussing as:

Jack: Hey, how are you, man?

Bill: Not bad, got married and I have three kids now.

Jack: That's awesome. How old are they?

Bill: The product of their ages is 72 and the sum of their ages is the same as your birth date.

Jack: Cool..But I still don't know.

Bill: My eldest kid just started taking piano lessons.

Jack: Oh, now I get it.

How old are Bill's kids?

What 4-letter word can be written forward, backward or upside down, and can still be read from left to right?

Before Mount Everest was discovered, what was the highest mountain in the world?

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

If you toss a coin 10 times and it lands heads up every time, what are the chances it will land heads up if you toss it again?

How many triangles can you find in this given picture?

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

I am five letter word that is under you.
If you remove my 1st letter, then I am over you.
If you remove my 1st and 2nd letters then I am all around you.

Who am I?