1. When school closes, a school uses a phone tree to contact each student's families. The Principal's secretary calls 3 families then each family call 3 other families, and so on. How many families will be notified during the 7th round of calls?
2. A certain bacterium splits into 2 bacteria every hour. There is 1 bacterium on a slide. If each bacterium on the slide splits one hour, how many bacteria will be on the slide after 8hrs? ​