Why Wine Glass Stem is so long?

Can you find out the missing number in the grid?

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

Can you solve the photo plexer logic ?

Make eight squares by moving only two matchsticks.
Note- Square can be of different sizes.

Decode the below four famous ciphers:

8P of the SS
1M of the E
1S of the SS
60M in 1H

A wooden log balances equally on the scales when weighed with three-quarters of a pound and three-quarters of a wooden log.

Can you calculate the weight of the entire wooden log?

If 21x = 79x, what is the value of x?

I am under you when I am whole.
I shift above you if you remove the first letter.
I come all around you if you remove the second as well.

Can you tell me who I am?

How old is your son? asked a man to his neighbour. My son is five times as old as my daughter and my wife is five times as old as my son. I am twice as old as my wife whereas my grandmother, who is celebrating her eighty-first birthday is as old as all of us put together.

How old is the man's son ?