Amotor boat travels 60 miles down a river in three hours but takes five hours to return upstream. find the rate of the boat in still water and the rate of the current.

Step-by-step explanation:

  speed = distance / time

The rate downriver is (60 mi)/(3 h) = 20 mi/h.

The rate upriver is (60 mi)/(5 h) = 12 mi/h.

The rate of the boat in still water is the average of these:

  (20 +12)/2 mi/h = 16 mi/h

The rate of the current is the difference between the boat speed and actual speed:

  16 mi/h - 12 mi/h = 4 mi/h

the answer is; biodiversity resulting from few ancestors

adaptive radiation occurs when a population is subjected to a large natural environment with spatial ecological variations. the parts of the population in the different ecologies begin to adapt to their local environments. due to non-random mating across the large populations, this causes the different populations from the large population to speciate within their local environments. they, therefore, diverge to different species sharing a common ancestor.