Can you replace the question mark with the correct number?

Christina is practising her dance steps along with her friends. In a particular sequence, all of them form a row. At that point, Niharika is standing in the 4th position from either end of the row.
Can you find out how many girls are practising together?

Three friends named Mr. Black, Mr. Yellow and Mr. Green enter a pub on a weekend night. They are wearing either a Black, Yellow or Green shirt.

Mr. Yellow says to them, 'Did you notice that we all are wearing different color shirts than our names?'

To this, the man who was wearing the Green shirt said. 'Wow, thats right.'

Can you identify who is wearing which colour shirt ?

In the below-given picture of a pretty girl, there is something wrong. Can you find out what it is?

What number comes next in this sequence:
7 8 5 5 3 4 4 _

How can a man go eight days without sleep?

I’m orange, I wear a green hat and I sound like a parrot. What am I?

Why is 6 afraid of 7?

What has six faces, but does not wear makeup, has twenty-one eyes, but cannot see? What is it?

Can you find out what is missing?

1 3 5
2 4 ?

Hint: It's not six. Think out of the box.