Can you find a five letter word that is left with only two letters if one is removed?

To attend world science seminar, A famous chemist from Mexico visit
London. In the lab, the scientist was killed and his six assistants were under suspicion of killing the chemist.
Name of six assistants: Austin, Wayne, Dege, Oscaru, Lingard, and Rojo.
He left a note "76-20-44 79-16-22-7"

A local detective Jack was called to solve the case,

After reading the note, Jack instantly asked the police to arrest the murderers.

Who are the murderers?

What can you serve, but never eat?

John and his wife were living in a rural place. On a particular day, John's wife fell ill and he called the local doctor. When the doctor picked up, he said, "Doctor, my wife is ill. She might have appendicitis."

"This can't be possible! I took out her appendix two years ago myself," the doctor explained.

When diagnosed, John's wife was found to have appendicitis. How can this be possible?

What has many keys but can’t open a single lock?

What is the last thing you take off before bed?

Can you count the number of triangles in the given figure?

What is full of holes but still holds water?

This is a classy optical illusion puzzle. What more you can find except bricks in the image below?

Why is 6 afraid of 7?