This actually landing tails or landing heads in this case? Well, it's either this side or this side. So it's 50 50 and that means there's a one half chance that this will land up and a one half chance that this will land up. So we see that the probability of it landing head the first time around is basically one half. So the probability of event number one taking place is one half and likewise the probability of independent event number two taking place, the second coil flip, coin flip is also one half. And because they're independent, to find the actual probability of these two events taking place we have to apply the product rule.