200 count / min
100 count / min
50 count / min
25 count / min
Correct answer is C
116 days = 4 half - lives
Thus, after 4 half lives the fraction left of any radioactive materials is given by (1/2)4 = 1/16
∴ Count rate / amount left = 1/16 x 800/1
= 50 count / min