Would you pass a perception IQ test?
Your job is to read the upcoming sentence. Read it at a moderate to quick pace, whatever suits you. While you are reading, count the number of f's in the sentence. The important thing is, don't go back to re-read it. Once you've read the sentence, give your answer.
And don't worry about the results. I myself failed it when it was given to me in class. They're not accurate, and this is just for fun.