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

Which alphabet is a part of our body?

We can be boring,Or interesting.
We can be long,Or short.
We can have pictures,Or just words.
Many love us,But many also hate us.
What are we?

Can you replace the question mark with the correct number in the below table sequence?

Buy me, smell me or deliver me, I do not change.

Who am I?

It is a nine-letter word.
The exact opposite of the phrase "friendly and outgoing"
It contains the word "over".
It starts will a vowel.

What is it?

Make the seating arrangement of 10 children in such a way that there are 5 rows with 4 children in each row.

I have four wings but can't fly.
I express no emotions.
I am found on the exact spot every time you look.
I keep toiling away with a little sound.

Do you know what am I?

Can you make numbers like 24, using numbers 3,3,7 & 7 with any arithmetic operator?

Can you name some countries which do not have the alphabet 'A' in them?