What has one letter and starts with an E?

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

I’m tall when I’m young, and I’m short when I’m old. What am I?

I hide my treasure in the ground, my tail is big and fluffy. If you spot me in a tree, please don’t call me scruffy. What am I?

If an electric train is travelling south, then which way is the smoke going?

I am taken from a mine and shut up in a wooden case, from which I am never released, and yet I am used by almost every person. What am I?

I am a five-letter word and comprises two different vowels and three same consonants. I am so strong that I can spoil your entire work.

Can you find out who am I?

I am a normal creature, but I have five hands. I can even have more but even then I will be considered normal.

Who am I?

Why 1729 is a magic number? Answer Logically.

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.