Problema Solution
A bacteria culture started with 9,000 bacteria and increased by 20% the first hour. Find the number of bacteria that will be present in 4 hours.
Answer provided by our tutors
start moment: 9,000 bacteria
after first hour: 9,000 + 0.20*9,000 = (1 + 0.20)*9,000
after 2 hours: 1 + 0.20)*9,000 + 0.20*(1 + 0.20)*9,000 = ((1 + 0.20)^2)*9,000
after 3 hours: ((1 + 0.20)^3)*9,000
after 4 hours: ((1 + 0.20)^4)*9,000 = 18,662 bacteria present.