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

A certain street contains 100 buildings. They are numbered from 1 to 100. How many 9's are used in these numbers?

What two things can you never eat for breakfast?

Can you convert the number zero(0) into a positive number using just one mathematical operator ?

Always in you, Sometimes on you;

If I surround you, I can kill you.

What am I?

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?

It can't be seen, can't be felt, can't be heard, and can't be smelt.
It lies behind stars and under hills, And empty holes it fills.
It comes first and follows after, Ends life, and kills laughter.
What is it?

If,

20 % 5 = 24

21 % 7 = 33

42 % 6 = 67

Then;

66 % 6 = ?

Find the next number in the series below.

6 18 270 72090 ?

In the given figure, move three matchsticks so that the resulting figure contains two rectangles.