No, answer is not 5 .. C'mon , counting letters is no rocket science !

its 6

gomi 

The answer is.... not 3 !

Neat how our mind works.

Mike

PandaWarrior 

its 6

Nice ! For some reason the brain doesn't "see" the OFs..

gomi 

Nice ! For some reason the brain doesn't "see" the OFs..

Yup, and imagine -- if we can't even process the word "of", then what other stuff is our mind playing tricks on us with? A lot... this became very apparent to me after I started journaling my trades. Before journals, I would always remember the event differently than how it actually happened. And this wasn't "selective remembering", I would have sworn I was remembering it accurately. And was wrong.

Mike

OK, this is my last try.

One because the actual question is talking about this sentence.
Then it would be none, not one, if the question is, How many letters f contains "This sentance?"

Thanks Wiki

gomi 

Nice ! For some reason the brain doesn't "see" the OFs..

On the contrary, brain is so powerful, but is biased toward experience. That is why majority can not think out of the box.

You can read the following at whatever your normal reading speed is. Try it.

Not giong to hit a 700 wrods/mnutie wtih tihs knid of txet, but stlil vrey rebadale idneed.

aligator 

On the contrary, brain is so powerful, but is biased toward experience. That is why majority can not think out of the box. You can read the following at whatever your normal reading speed is. Try it.

that was easy

Ok this one is for those who like colored charts: