Irene killed hundreds of people mercilessly and yet the police were not able to put her behind the bars. Why?

Can anyone tell me a word in the English dictionary which has a silent 'z'?

I am a five-letter word under you,
Remove the first letter and I am above you,
Remove the second as well and I am around you.

Who am I?

All of the flowers I have are orchids except two. All of the flowers I have are hibiscuses except two. All of the flowers I have are roses except two.

Can you tell me how many flowers I have?

A man dies of old age on his 25 birthday. How is this possible?

What number when divided in half becomes zero?

The square root of number 121 is "11". What is the square root of the number "12345678987654321."?

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?

Keyboard words are not in alphabetical order, Why?

If nine thousand, nine hundred nine dollars is written as $9,909,
how should twelve thousand, twelve hundred twelve dollars be written?