Blood alcohol content, reflex time for a single person

What are potential hypotheses (explanations) regarding why there are ecological equivalents between many metatherians and eutherians? discuss your hypothesis in terms of the processes that could lead to the current ecologies and distributions of metatherians and eutherians.

What is the range? can’t seem to find it out

For what value of (y) is 3^3/3^y =1/9