What happened when the wheel was invented?

What does this simple rebus mean?

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?

Look at the below sequence of letters and tell us what the next letter should be:

O T T F F S S ?

There once were seven dwarfs who were all brothers. They were all born two years apart. The youngest dwarf is seven years old. How old is his oldest brother?

Begin with a word, five letters to my name,
Remove the first and last but I am the same
Take out my middle and still, I remain.
What word am I?

If one and a half boys, eat one and a half burgers in one and a half hours.

How many burgers can 9 boys eat in 3 hours?

Which is the smallest number that you can write using all the vowels exactly once?

Sherlock Holmes was challenged to make a pre-drawn line smaller without erasing it. He did it in fractions of seconds. How?

It has a long neck, A name of a bird, Feeds on cargo of ships, It's not alive,

What is it?