Use the Following Information to Answer the Questions
a Radioactive $H_{p}$

Multiple Choice

Use the following information to answer the Questions
A radioactive element used in medicine has a physical half-life $H_{p}$
(the time in which half of any quantity of the element decays) and a biological half-life $H _ { b }$ (the time in which half of an amount of this element in the body is excreted) . The effective half-life $H _ { e }$ is calculated from $\frac { 1 } { H _ { e } } = \frac { 1 } { H _ { p } } + \frac { 1 } { H _ { b } } .$
-The physical half-life of iron-59 is 45 days and its biological half-life is 600 days. Find the effective half-life of iron-59.

A) 40.4 days
B) 41.9 days
C) 322.5 days
D) 645 days