Posted by Alexia on Sunday, April 10, 2011 at 7:04pm.
Nuclear medicine technologists use the Iodine isotope I131, with a halflife of 8 days,to check thyroid function of patients. After ingesting a tablet containing the iodine, the isotopes collect in a patient's thyroid, and a special camera is used to view its function. Suppose a person ingests a tablet contaiing 9 microcuries of I131. To the nearest hour, how long will it be until there are only 2.8 microcuries in the person's thyroid?

Math please help!  bobpursley, Sunday, April 10, 2011 at 7:10pm
2.8=9*e^(6.93 t/(8*24))
ln (2.8/9)=6.93 t/182
solve for t in hours. I get about 31 hours 
Math please help!  Alexia, Sunday, April 10, 2011 at 7:13pm
the answers are given, it is 324 hours. im just not sure how to get that.

Math please help!  Alexia, Sunday, April 10, 2011 at 7:17pm
where did you get 6.93 and 24 from?

Math please help!  Mgraph, Sunday, April 10, 2011 at 7:47pm
m(t)=9x2^(t/192) 192=24x8
2.8=9x2^(t/192)
t=192xln(9/2.8)/ln2
t=323.4236495