If a parent isotope has a half-life of 10,000 years, how long will it take to get to a 1:3 ratio?
My brother is living with a drug dealer who has been his best friend for 10 years. I do not approve of this lifestyle and my parents are unaware of it. The kid moves weight (at least 1-1 1/2 lb of pot a week plus hallucinogens). How do I get the kid out of his life?