What number when divided in half becomes zero?

How high do you have to count before you use the letter “a” in the English spelling of the whole number?

During which month do people sleep the least?

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?

Using the clues below, what four numbers am I thinking of?

The sum of all the numbers is 31.
One number is odd.
The highest number minus the lowest number is 7.
If you subtract the middle two numbers, it equals two.
There are no duplicate numbers.

I look at you, you look at me, I raise my right, you raise your left. What am I?

What does this rebus riddle means ?

Look at this sequence from top to bottom. What is the next number in the sequence?
1
11
21
1211
111221
312211

Can you divide the below-given shape into four equal and identical pieces?

What word begins and ends with an E, but has only one letter?