Many have heard it, but nobody has ever seen it, and it will not speak back until spoken to. What is it?

What part of the chicken has the most feathers?

Replace the letters of words with a number so that the below equation holds true

BASE +
BALL
---------
GAMES
----------

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?

Pronounced as one letter,
And written with three,
Two letters there are,
And two only in me.
I am double, I am single,
I am black blue and grey,
I am read from both ends,
And the same either way.

Assume there are approximately 5,000,000,000 (5 billion) people on Earth. What would you estimate to be the result, if you multiply together the number of fingers on every person's left hand? (For the purposes of this exercise, thumbs count as fingers, for five fingers per hand.) If you cannot estimate the number then try to guess how long the number would be.

A father's child, a mother's child, yet no one's son.

Who am I?

What mathematical symbol can be put between 5 and 9, to get a number bigger than 5 and smaller than 9?

In a concert, Christina is performing a dance show with her group.
At 10:00, she and her crew were dancing in an absolutely straight line. At that time Christina was standing in 4th position from both the front and back end of the row.

What was the size of her crew?

If 1+9+8=1, what is 2+8+9?