It walks on 4 when its young, walks on 2 when it's older, and walks on 3 when its very old?

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

What do you see in the image below

A man is found dead in his bathroom naked with blood scattered all around him. The bathroom was locked from the inside and there is no trace of any struggle. There is nothing in the bathroom except his pant with the belt still around and his shirt. Also, the medic team can't find any incision in his body that may have been the reason behind so much blood loss.

The Police department is clueless regarding this murder mystery.
Can you?

What word is pronounced the same if you take away four of its five letters?

Considering the below equation:

V + II - VI = 10
IV - X + VIII = 20
IV - VII + VI = 30

Then, I + II + III = ?

I cry without having a voice.
I fly without having wings.
I bite without having teeth.
I whisper without a mouth.

Who am I?

Decode below three cipher riddles:

26 L of the A
7 D of the W
1000 Y in a M

I speak without a mouth, and hear without ears. I have no-body, but I come alive with the wind. What am I?

Can you decipher the two rows to find the hidden word?