Find the value of "?" in the ball picture Riddle below:

Always in you, Sometimes on you;

If I surround you, I can kill you.

What am I?

If you go to the movies and you're paying, is it cheaper to take one friend to the movies twice, or two friends to the movies at the same time?

I am the black child of a white father, a wingless bird, flying even to the clouds of heaven. I give birth to tears of mourning in pupils that meet me, even though there is no cause for grief, and at once on my birth, I am dissolved into air. What am I?

A little girl goes to the store and buys one dozen eggs. As she is going home, all but three break. How many eggs are left unbroken?

What runs around the whole yard without moving?

What always comes into a house through the keyhole?

Can you find the missing letter in the sequence?
S - T - I - L - ? - T - F - Y - C

A cat had three kittens: Snophy, Topsy and Jorden. What was the mother's name?

You are stuck on an island where you have nothing. You find four pieces of paper somewhere on the island. What will be your strategy to escape from the island safely?

PS: No other resource is available to you on the island, neither can you build anything.