How did a small minority of 8% white people wind up ruling the country of South America?

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

Can someone me? i need to have this done as soon as possible! i'm putting 20 points on this!

Read the article titled "greening the globe." according to the section titled “the contention,” the debate over climate change has two basic camps of thought. identify these two camps and their beliefs. give examples of who supports each one and explain what evidence they use to support their arguments. based on these arguments, which way of thinking do you agree with and why?