I’m light as a feather, yet the strongest person can’t hold me for five minutes. What am I?

Count The number of F's in the paragraph below:

"FINISHED FILES ARE THE RESULT OF YEARS OF SCIENTIFIC STUDY COMBINED WITH THE EXPERIENCE OF YEARS"

I am a type of food that is often found in the fridge and can be white in colour. What I am?
Hint 1: I am a dairy product.
Hint 2: You can spread me on the bread.

How can you write nineteen in a manner that if we take out one, it becomes twenty?

It comprises roots which nobody sees,
Much taller than those trees,
Up and up it goes,
Still it never grows?

If an electric train is travelling south, then which way is the smoke going?

Samuel was out for a walk when it started to rain. He did not have an umbrella and he wasn't wearing a hat. His clothes were soaked, yet not a single hair on his head got wet. How could this happen?

John was piloting a plane behind a car but was never able to overtake it. Why?

What have one eye but still cannot see?

I get hot but I never sweat,
I cook food but I am not a chef,
I have a door but you can't enter me,
I have a light but I am not a lamp.
Who am I?