Can you find the mistake in the below statement?

Can you write down eight eights so that they add up to one thousand?

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

There are five vowels (a, e, i, o, u) in the English language.
Can you tell us a word that contains all these vowels?

A certain street contains 100 buildings. They are numbered from 1 to 100. How many 9's are used in these numbers?

How many letters are in the alphabet?

Can you name any English verb that becomes its past tense by simply rearranging the alphabets ?

I have an eye but still cannot see.

Who am I?

This is a most unusual paragraph. How quickly can you find out what is so unusual about it? It looks so ordinary, you'd think nothing was wrong with it. Actually, nothing IS wrong with it. But it is not as ordinary as you might think. If you think about it for a bit, you will find out why it is truly so unusual. So what is it? What is so unordinary about this paragraph?

What is the Surname of Barbie Doll?