There is a crack in your basement wall that allows Neptunium-236 to seep in. Np-236 has a half-life of 22.5 hours. You seal your wall and find there is 10 grams of Np-236 in your basement. How many grams of a 10.0 gram sample would have decayed after exactly three half-lives? Now imagine, your seal was insufficient and every 22.5 hours, 5 grams of Np-236 was still able to seep through. After 75 hours, how many grams of Np-236 would have decayed?