Brad flips a coin 3 times what is probability it will land heads up all 3 times?

assuming it's the coin that can land on "heads" and not Brad, also assuming that the coin is perfectly uniformly dense and has a uniform shape and the thing the coin lands on is perfectly still (probably not Brad's head), and has a constant coefficient of friction for wherever the coin touches it, and a constant air friction coefficient, I would say 3/8. or we can accept the fact that there are two sides to a coin, the probability of one side landing up is 1/2, if rolled 3 times, probablility = 3 * .5 *.5 *.5 just perform an experiment