Arecent survey shows that the probability of a college student drinking alcohol is 0.6. further, given that the student is over 21 years old, the probability of drinking alcohol is 0.8. it is also known that 30% of the college students are over 21 years old. the probability of drinking or being over 21 years old is

The smokey mountains have over 2,100 miles of rushing mountain streams and rivers that flow through the park. in each mile lives a diverse community of native fish, amphibians, insects, and larvae, some of which are found only in the southern appalachians. park managers and scientific researchers test many factors such as fish populations, the watersheds and water tests to determine a) too many lizards are present b) the water quality of the stream c) rainwater is running into local streams d) if visitors to the park are overstaying their welcome