Please HELP im preparing for my math exam tomorrow and i need help solving these types of questions I will give you brainliest and 5 stars and heart please help I was always bad at these types of questions

The length of a ribbon roll is 2.5 m. If 50 cm has been used from it, how much is left?

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.  

the answer is 40.

proof: