I need help very quickly! There are approximately 7.7 billion humans on Earth. If the virus spreads beyond the 200-person town, how long will it be until everyone on the planet is infected? Another part of the question is "Some viruses are more contagious than others. Instead of passing the virus to one new person, imagine each infected person passes it to three. How will this affect how long it takes for the virus to infect everyone on earth?"