Quickly Solve this riddle

7 - 4 + 3 * 0 + 1 = ?

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

Pronounced as one letter,
And written with three,
Two letters there are,
And two only in me.
I am double, I am single,
I am black blue and grey,
I am read from both ends,
And the same either way.

You can hear me, but you can't touch or see me.

What am I?

who is silent in the parliament?

A person was found dead on a big green land with no trees or buildings around. When the police arrived, they found a piece of rock lying next to him and the man was wearing clothes comprising of red, blue and yellow colours.

Can you tell who the person is and what was the cause of death?

Replace the letters of words with a number so that the below equation holds true

BASE +
BALL
---------
GAMES
----------

I welcome the day with a show of light, I stealthily came here in the night. I bathe the earthy stuff at dawn, But by noon, alas! I'm gone.

I am a three digit number.
My tens digit is five more than my ones digit.
My hundreds digit is eight less than my tens digit.
What number am I?

Count the number of triangles in the given picture.