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

SEVEN + SEVEN + SIX = TWENTY.

What are the digits ?

Replace each alphabet with the number (1-9) to make the below equation correct.

AB * C = DE - F = GH / I

What's the only room from which no one can enter or leave

Three brothers Jacob, John, and James live in Mexico City. The product of the ages of these brothers is 175. Jacob and John are twins. How old is James?

What has many teeth, but cannot bite?

If there are fifteen crows on a fence and the farmer shoots a third of them, how many crows are left?

How can you tell a raw egg from a hard-boiled egg?

I am taken from a mine and shut up in a wooden case, from which I am never released, and yet I am used by almost every person. What am I?

In a rainy season, one day 3 huge ladies walked under a normal-sized umbrella.
The umbrella is not huge enough to accommodate all 3 ladies yet not a single lady got wet. Why?

If 24H in a D => 24 hours in a day.
What does "64S on CB" stand for?