Decay constant or mean life from two activity readings

1. A.
   $\frac{t_{2} - t_{1}}{\ln5}$
2. B.
   $\frac{\ln\left( t_{2} + t_{1} \right)}{2}$
3. C.
   $\frac{t_{1} - t_{2}}{\ln5}$
4. D.
   $\frac{\ln5}{t_{2} - t_{1}}$

Tap an option to check your answer.

1. A.
   $0.02{\text{ }\min}^{- 1}$
2. B.
   $2.7{\text{ }\min}^{- 1}$
3. C.
   $0.063{\text{ }\min}^{- 1}$
4. D.
   $6.3{\text{ }\min}^{- 1}$

Tap an option to check your answer.