There are 43 different books in the ' crazy silly school ' series. If you are yet to read 33 of the books How many books have you already read?
There are 43 different books in the 'crazy silly school' series. 
If you are yet to read 33 of the books, 
How many books have you already read?

There are 43 different books in the 'crazy silly school' series. 
If you are yet to read 33 of the books, 
that means you have read 10 of the books.