Every words stands for unique digit that makes the arithmetic equation true

SEVEN + SEVEN + SIX = TWENTY.

What are the digits ?

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 = ____

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

What can you see in the middle of March and April that you can never see in any other month?

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

Samuel was out for a walk when it started to rain. He did not have an umbrella and he wasn't wearing a hat. His clothes were soaked, yet not a single hair on his head got wet. How could this happen?

A finger goes in me. You fiddle with me when you're bored. The best man always has me first. What am I?

John is selling fruits.
He sells grapes at $30, Dates $25, and a Wolfberry $45.
At what price does he sell fig?

PS: Logical Thinking

It has a long neck, A name of a bird, Feeds on cargo of ships, It's not alive,

What is it?

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