Replace the question mark with the number below given a simple math problem.

Why Wine Glass Stem is so long?

Can you find out the number of the parking space in which the car is parked?

Below, you can see three complete equations and one incomplete. Based on the three complete ones, can you complete the incomplete one?

5 $ 4 $ 3 $ 9 = 4215
6 $ 9 $ 2 $ 6 = 3816
4 $ 7 $ 3 $ 3 = 1122
7 $ 2 $ 7 $ 4 = ____

I am weightless, but you can see me. Put me in a bucket, and I'll make it lighter. What am I?

Detective Rockford was jogging near the beach at 4:30 am.
He hears a sound near the shack "No Michael, Please Do not shoot me".
Next instance he heard the sound of gunfire. Rockford rushes to the shack where he finds women lying dead and a gun in close proximity of three "Doctore Lawyer and a Teacher".

Rockford immediately knew that the Lawyer has committed the crime. How?

What has a bottom at the top?

When I get multiplied by any number, the sum of the figures in the product is always me. What am I?

Yesterday I fell from 30 feet high ladder but I don't get hurt. Why?

The owner of a popular clothing store comes up with his own method of pricing items. A vest costs $8, socks cost $10, a tie costs $6, and a blouse costs $12. Using the owner’s method, how much would a pair of underwear cost?