I'm desperate and too lazy to go to google, please help. Thanks♡

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

Which of the following best describes asbestosis?

Asegment whose endpoints are points on the edge of the circle are whatps: i ment to put this under geometry i apologize ; ;