What Adam and Eve do not have but the rest of the people have?

How do you go from 98 to 720 using just one letter?

I never was there, I am always to be.
You have never ever seen me, not ever you will.
Yet I am the confidence of everyone.

Who Am I?

There's a day, that comes around once a year.
To celebrate the man, you hold dear.
He gave you life, love and will pick you up if you fall.
When it comes to guys like him, He's the best of all.
Who is he?

I am an eight letter word and I am a computer terminology.
The second, third and fourth letters make an animal.
The fourth, fifth, sixth, seventh and eighth letters make a weapon.
The first, second, third and fourth letters can be taken as an outcome of any exam.
The fifth, sixth, seventh and eighth letter combine to form a high end typing software.

Can you tell who am I ?

I possess a head

I flaunt a tail

But I don't have mouth or legs

Can you find out who I am?

There is a square of a particular number which when doubled, becomes 7 more than its quarter.

Can you find the number?

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.

Analyze and find the missing item in the sequence:
16, 06, 68, 88, __, 98

Take 9 from 6, 10 from 9, 50 from 40, and leave 6.

How Come ??