Can you spot what's wrong with the following sentence?

PETER WAS ANGRY AT
HIMSELF BECAUSE HE
ACCIDENTALLY LEFT THE
THE KEYS TO HIS CAR
AT HIS FRIEND'S HOUSE.

Always in you, Sometimes on you;

If I surround you, I can kill you.

What am I?

There are a number of books on a shelf. If one book is the 4th from the left and 6th from the right, how many books are on the shelf?

How many times can you subtract the number 5 from 25?

I am looking for a word that change both gender and number when i add the letter 'S'.

What Word am I Looking For ?

I am a white box having no key or lid.
Yet there is a golden treasure inside it.

What Am I?

I have a head like a cat and feet like a cat, but I am not a cat. What am I?

A new Engineering building containing 100 offices had just been completed. John was hired to paint the numbers 1 to 100 on the doors. How many times will John have to paint the number nine (9)?

Count the number of times the letter "F" appears in the following paragraph:

FAY FRIED FIFTY POUNDS OF
SALTED FISH AND THREE POUNDS
OF DRY FENNEL FOR DINNER FOR
FORTY MEMBERS OF HER FATHER'S FAMILY.

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?