You may enter, but you may not come in. I have space, but no room. I have keys, but open no lock. What am I?

I am a seven-letter word but if you remove four of my letters I will have one left. What word am I?

How many times can you subtract the number two from the number fifty?

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)?

I know a nine-letter word having only one vowel.
Do you ?

I am dry when I go inside, but wet when I am pulled outside.
The longer I am inside, the stronger I get
When I am completely out, I am wet and I literally sag
Who am I?

How many letters are in the alphabet?

My first is in chocolate but not in ham. My second is in cake and also in jam. My third at tea time is easily found. Altogether, this is a friend who is often around. What is it?

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.

They do not possess flesh or feathers or scales or bone
But still, they are blessed with fingers and thumbs of their own.