A particular radioactive isotope decays from 230 milligrams (mg) to 200.1 mg in 8 days. Find the half life of the isotope. Hint: Find the rate first....

A particular radioactive isotope decays from 230 milligrams (mg) to 200.1 mg in 8 days. Find the half life of the isotope. 

Hint: Find the rate first. The half life of the isotope is the half value of 230 mg then solve for x. 

Your answer is days.