A rumor starts with two people. The rumor triples every five minutes. How many people will know the rumor after 1 hour?

Answer 1

This is an exponential growth problem. The tripling period in hours is 5/60 = 1/12

N = number of people who know the rumor after t hours

N(t) = N₀ (3)^t/(5/60) = N₀ (3)^60t/5 = N₀ (3)^12t

N₀ = initial number = 2

N(t) = 2 (3)^12t

Plug in t in hours.