Question

The half life of ${}^{58}$$Co$ is $72$ days. Its average life is:

• A. $102.9days$
• B. $103.9days$
• C. $104.9days$
• D. $105.9days$

Answer 1

The correct option is B $103.9days$

$t_{1/2}=72days$

$t_{avg}=\frac{1}{\lambda }=\frac{t_{1/2}}{0.693}$$=\frac{72}{0.693}$$=103.9days$