A small amount of solution containing a radioactive nuclide A was administered into blood of a patient. The activity of the nuclide is `2 xx 10^(3)` dps. Its half life is 15 hours. After 5 hours a sample of the a sample of the blood drawn out from the patient. It's activity was 16 dpm per mL.
What is the volume of the 'blood' in the patient ? `(log (1.26) = 0.1)`

Options

A. 2.92 lit
B. 3.95 lit
C. 4.92 lit
D. 5.95 lit

Answer

D

Explanation

Initial activity ` = 2 xx 10^(3)` dps after 5 hours the activity is = x
`therefore (0.693)/(15) = (2.303)/(5) log "" (2 xx 10^(3))/(x) " " therefore x = 1.588 xx 10^(3)` dps
So `1.588 xx 10^(3) xx 60 = 16 V, " "V = 5.95` lit