if 1 person with corona spreads it to 3 people and those people spread it to 3 people, how many people have corona
So the spread rate is 3/1 = 3.
If 3 people have it, then they spread it to 3 x 3 = 9 people.
So the spread rate is 3/1 = 3.
If 3 people have it, then they spread it to 3 x 3 = 9 people.