What number should come in place of the question mark below?

What begins with T, ends with T, and has T in it?

I make two people out of one. What am I?

How can you tell a raw egg from a hard-boiled egg?

What breaks yet never falls, and what falls yet never breaks?

Its something that each of us devours,
Not just us but birds, beats, trees, and flowers,
Frets iron and nibbles steel,
Toil hard stones to meal,
Exterminates king, collapse town,
And blows the mountains down.

Which word is least like the others? Third, fourth, fifth, sixth, seventh, eighth, ninth?

Count the number of lines in the image below ?

What happened when the wheel was invented?

Three ants are sitting at the three corners of an equilateral triangle. Each ant starts randomly picks a direction and starts to move along the edge of the triangle. What is the probability that none of the ants collide?