A culture started with 2,000 bacteria. After 2 hours, it grew to 2,400 bacteria. Predict how many bacteria will be present after 10 hours?
Growth with bacteria is exponential, so we can consider that we are working with a G.P.
If we regard 2 hours as being one time unit, 10 hours is a further 4 units of time. (6th term)
Either 4 more starting with 2400 bacteria,
or 5 time units starting with 2000 bacteria.
After 10 hours: 2000 xx 1.2^5 = 4977 bacteria.