In this question, the population of the bacteria will become half after 6 hours and the duration (2 days=48 hours) and the final amount of bacteria (400 bacteria), To find the number of bacteria at the start(initial number), the calculation would be:
Final number = initial number / 2^(duration/6hours)
400= initial number / 2*(48/6)
initial number = 400 * 2^8= 102,400
