Yesterday I fell from 30 feet high ladder but I don't get hurt. Why?

The person who makes it has no need for it. He who purchases it does not use it. The person who does use it does not know they are. What is it?

I am a type of word that is spelt incorrectly or used differently, on purpose for humour. What am I?
Hint 1: You can find me in a joke.
Hint 2: I am a play on words.

Solve The below Equation:

ALFA + BETA + GAMA = DELTA

The day before yesterday I was 25 and the next year I will be 28. This is true only one day in a year. What day is my birthday?

The dirtier I get, the whiter I look. Who am I?

John is a strange liar.

He lies on six days of the week, but on the seventh day, he always tells the truth.

He made the following statements on three successive days:

Day 1: "I lie on Monday and Tuesday."
Day 2: "Today, it"s Thursday, Saturday, or Sunday."
Day 3: "I lie on Wednesday and Friday."

On which day does John tell the truth?

John was gifted a new Hayabusa. He drove x miles at 55mph. Then he drove x+20 miles at 40mps. He drove his bike for 100 minutes. How much distance did he travel?

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?

Do You See It?