What has one letter and starts with an E?

A boy purchased a book from a bookkeeper and gave him $100.
The cost of the book is $50 but the bookkeeper has no change, so he gets the change from the next shop and returns the boy his $50.

After some time the next shopkeeper came with the $100 note and told the bookkeeper that the note was a fraud, so he took the money back.

How much loss did the bookkeeper face?

I am a three digit number.
My tens digit is five more than my ones digit.
My hundreds digit is eight less than my tens digit.
What number am I?

Spelt forwards I’m what you do every day, spelled backwards I’m something you hate. What am I?

What jumps when it walks and sits when it stands?

Make a sentence consisting of three words that have the whole alphabet.

Find the combined weight of the Cat, Dog and Rabbit in the given picture.

A rubber ball keeps on bouncing back to 2/3 of the height from which it is dropped. Can you calculate the fraction of its original height that the ball will bounce after it is dropped and it has bounced four times without any hindrance ?

If you remove one from eleven, it becomes ten. If you remove one from nine, it becomes ten.

How is this possible?

What numbers should go on the bottom line?
3 6 9 15
8 2 10 12
11 8 19 27
19 10 29 39
? ? ? ?