Phosphorus-32 Is a Radioactive Isotope Used in Many Biomedical Applications

Phosphorus-32 is a radioactive isotope used in many biomedical applications.How much phosphorus-32 was originally used if there are only 3.50 mg left in a sample after 288 h? The half-life of phosphorus-32 is 14.3 days.)

A) 1.96 mg
B) 6.26 mg
C) 4.17 mg
D) 7.00 mg
E) 17.9 mg