At noon a bacteria was 160,0000, four hrs it was 50,0000 at the exponential rate what is tha bacteria count at

Question

At noon a bacteria was 160,0000, at four hrs it was 50,0000 at the exponential rate what is tha bacteria count at midnight?

Answer 1

4 hours after? Then we're looking at a bacterial half-life of 2 hrs, since it decreases by a factor of 4 in 4 hrs. Then at midnight, 8 hrs or 4 more half-lives have elapsed, so the bacteria count is 50,000/2^4 = 50,000/16 = 3125.