Erika has received scores of 82, 87, 93, 95, 88, and 90 on math quizzes. what score must erika get on her next quiz to have an average of 90?

Characteristics of substance farming include all of the following except

How does water pollution affect the environment

Geologists know that potassium-40 decays to argon-40, with a half-life of 1.3 billion years. if an analysis of a feldspar crystal in a sample of granite shows that 75 percent of the potassium-40 atoms have decayed to form argon-40, what is the age of the granite