How to find the half-life of a radioactive isotope?

Which of the following best supports the concept that genetic information is passed on to offspring from both of their parents, not just one?

11. phosphorus-32 is radioactive and has a half life of 14 days. how much of a 124 mg sample of phosphorus-32 is present after 56 days? a) 7.75 mg b) 15.5 mg c) 31.0 mg d) 62.0 mg

What is the vapor pressure of a solution with a benzene to octane?