Question

A scientist counts 25 bacteria present in a culture and that number triple each hour. When will there be about 1170 bacteria in the culture?

Answer 1

25 bacteria at time = 0
population triples each hour
population = 25 * (3^time)

We have to solve that equation for time so we
take logarithms of both sides:
population / 25 = (3^time)
log(1,170 / 25) = time * log(3)
log(46.8) = time * log(3)
1.6702458531 = time * 0.4771212547
time = 1.6702458531 / 0.4771212547
time = 3.5006737523 hours

Double check
population = 25 * (3^3.5006737523)
population = 25*46.8
population = 1,170