A small pump can drain a pool in 9 hours. A large pump could drain the same pool in 3 hours. How long (to the nearest minute) will it take to drain the pool if both pumps are used simultaneously?

22.5 hours

Step-by-step explanation:

Let t be the time taken by both of the pumps to drain the pool.

Given: Time taken by pump 1 to drain the pool alone= 9 hours.

Time taken by pump 2 to drain the pool alone= 3 hours.

If  both pumps are used simultaneously, then

Hence, it will take 22.5 hours to drain the pool if both pumps are used simultaneously.

i belive those are the ones that are under 90 degreese.

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.