someone help me please, i will give brainliest this is due soooooon!1111

Answer:
216
Step-by-step explanation:
I'm sure there is a simpler way to do this but this is how I did it.
First divide 18 by 6 because it triples every 6 hours.
18/6=3
This means it will triple three times
Then triple the value three times
#1. 8x3=24
#2. 24x3=72
#3. 72x3=216
In 18 hours the virus will infect 216 people.