Puzzle #231: Zombies

Being an editor requires a certain amount of brains. The zombie apocalypse has struck Kamloops, and the zombies are going after the smart people first.

Let us join Sean Brady, editor of The Omega (the TRU student newspaper), as from his well-fortified office, he fights off a small band of zombies. There are four zombies. Three of them could each alone break through Sean’s defences in eight hours. The fourth zombie could do so alone in six hours.

Sean has called the police, but not surprisingly, they are busy.

One hour into the battle, Sean scores a lucky hit and takes out an eight-hour zombie. He does not manage to do any other damage that affects their ability to break through.

Exactly two hours after he called the police, they show up.

Do they find Sean still fighting and quickly despatch the zombies with rather more effective weapons than dictionaries and writing guides? Or maybe, the zombies have eaten Sean’s brain and have gone off to the Kamloops This Week office to see about munching on Christopher Fould’s brain? Which is it?

Submit your answer to Gene Wirchenko <genew@telus.net>. Your answer should be in the form of a proof. That means to show how your answer must be correct. The deadline is Wednesday, I will post the answer shortly after.