It comprises roots which nobody sees,
Much taller than those trees,
Up and up it goes,
Still it never grows?

You have a three-gallon and a five-gallon measuring device. You wish to measure out four gallons.

I’m light as a feather, yet the strongest person can’t hold me for five minutes. What am I?

Jim and Sarah are in a long-distance relationship. Jim buys an engagement ring for Sarah and wants to mail it to her. Unfortunately, the only way to ensure the ring will be received is to place a lock on the package. Jim has locks and Sarah has locks, but neither has keys for each other’s locks. How can they make sure the ring isn’t stolen?

How many triangles can you find in this given picture?

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?

You see a boat filled with people, yet there isn’t a single person on board. How is that possible?

Next Number in the Series,

5, 16, 49, 104, ?

I am thinking of a five-digit number such that:
The first and last digits are the same, their submission is an even number and multiplication is an odd number and is equal to the fourth number. Subtract five from it and we obtain the second number. Then divide into exact halves and we get the 3rd number.

What number I am thinking of?

What will you call your mother's brother's brother-in-law?