Find the next number in the sequence

1, 2, 6, 21, 88, __?

Which alphabet is a part of our body?

There are five vowels (a, e, i, o, u) in the English language.
Can you tell us a word that contains all these vowels?

Find The Next Number in this series.
1, 2, 6, 42, 1806 ?

You have a 12 liters jug full of water. You have two empty 8 liters and 5 liters jug. How can you divide the water into two equal parts using these jugs?

The barber of Town shaves all men living in the town. No man living in the town is allowed to shave himself. The barber lives in that town. Who then shaves the barber of the town?

2, 3, 5, 9, 17, _ What is the next number in the sequence?

A man hijacks an aeroplane transporting both passengers(8 of them) and valuable cargo. After taking the cargo, the man demands nine parachutes, puts one of them on, and jumps, leaving the other eight behind. Why did he want eight?

Rebus Puzzle Definition: A rebus is an illusion device that uses pictures to represent words or parts of words.
What does This Rebus Puzzle Identify?

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.