A medical researcher is studying the spread of a virus in a population of 1000 laboratory mice. During any week, there is a 70% probability that an infected mouse will overcome the virus, and during the same week there is a 40% probability that a noninfected mouse will become infected. Four hundred mice are currently infected with the virus. How many will be infected next week and in 3 weeks?

(a) next week mice rilex

(b) in 3 weeks mice