Edgar earns $12 per hour at his job during his weekdays. his hourly earning increased by 50% when he works during weekends. edgar worked 20 hours this week on weekdays. what is minimum whole number of hours edgar will have to work during this weekend in order to earn at least $400 this week?

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