using four eights (8) and a one (1) and one mathematical symbol , create the number 100

Replace the (?) with the correct mathematical signs to make the expression equal to 59.

18 ? 12 ? 4 ? 5 = 59

Can you name three consecutive days without using the words Monday, Tuesday, Wednesday, Thursday, Friday, Saturday, or Sunday?

Use only one mathematical symbol and all numbers (0-9) to get a sum of 99

If 21x = 79x, what is the value of x?

Luis Garavito killed Density x Volume.

Who is Luis Garavito ?

You balance a broom horizontally on your finger such that your finger is present at the centre of the gravity of the broom (precisely). You mark the spot and cut the broom into two halves. You are left with two pieces - one long piece with the handle and one short piece with bristles and a portion of the handle.

If you weigh both the pieces now, what will happen?
a) The longer piece weighs more.
b) The shorter piece weighs more.
c) Both pieces weigh equally.

A man is sitting in a pub feeling rather poor. He sees that the man next to him is extremely rich. He turns to the rich man and says to him, 'I have an amazing talent; I know almost every song that has ever existed.'
The rich man laughs.
The poor man says, 'I am willing to bet you all the money you have in your wallet that I can sing a genuine song with a lady's name of your choice in it.'
The rich man laughs again and says, 'OK, how about my daughter's name, Joanna Armstrong-Miller?'
The rich man goes home poor. The poor man goes home rich.

What song did he sing? A man is sitting in a pub feeling rather poor. He sees the man next to him pull a wad of £50 notes out of his wallet. He turns to the rich man and says to him, 'I have an amazing talent; I know almost every song that has ever existed.' The rich man laughs. The poor man says, 'I am willing to bet you all the money you have in your wallet that I can sing a genuine song with a lady's name of your choice in it.' The rich man laughs again and says, 'OK, how about my daughter's name, Joanna Armstrong-Miller?' The rich man goes home poor. The poor man goes home rich. What song did he sing?

I am a type of vehicle that has two wheels and is powered by humans. What am I?
Hint 1: You can ride me for exercise.
Hint 2: I am environment-friendly.

Can you solve this amazing hard number series problem?
7, 8, 10, 12, 16, 18 ?