Physics - Modern Physics Question with Solution | TestHub

The half-life of ${\mathrm{Tc}}^{99}$ is 6 hour. The activity of ${\mathrm{Tc}}^{99}$ in a patient, 60 hour after receiving an injection containing this radioisotope is at least $0.125\mu \mathrm{ci}$. What was the minimum activity (in $\mu \mathrm{ci}$ ) of the sample injected ?