Now the six NADH because they're produced directly in the matrix of the mitochondria. Each one of these nadhs produces 2.5 ATP molecules and six multiplied by 2.5 gives us 15. Now, recall that when a single fadh two is oxidized by the electron transport chain, it is oxidized by complex two. And so we bypass complex one. And that means when a single fadh two is oxidized by complex two, complex two doesn't actually pump any protons. And so those electrons extracted from fadh two ultimately end up being transported onto complex three.