Question

Atlantic sea turtle eggs that incubate below 23°C or above 33°C rarely hatch. Write the temperature requirements in two ways: as a pair of simple inequalities, and as a compound inequality.

Answer 1

If the temperature of the egg is x, then if x is below 23 (x<23), they rarely hatch. If x is greater than 33 (x>33), they also rarely hatch. For them to not rarely hatch, then x must be not below 23 (greater than or equal to) and not above 33 (less than or equal to), resulting in our compound equality being 
23≤x≤33 and our pair of simple inequalities being x≥23 and x≤33.