I think 360 is just the number of bees within 30 days, well we have to add the starting bees, so 360+27=387
No, not quite. There were 27 bees when they were discovered. After 3 days, there were 36 bees. Right?
What was the INCREASE in 3 days?
36 / 27 = 1.333333..........There was an increase of 33.33% over 3 days. And after 30 days?
30 / 3 = 10 periods of 33.33% INCREASE, because the bees are multiplying "exponentially". That means:
(1.3333333.....)^10 =17.7577 - this is the total growth in the population of the original 27 bees.
So, 27 x 17.7577 =479.458 = ~479 bees after 30 days.