The density of the liquid as measured by the first student is:
\[
\boxed{\rho_{\text{container}} = \frac{m_{\text{liquid, container}}}{V_{\text{container}}}}
\]
The density of the liquid as measured by the second student is:
\[
\boxed{\rho_{\text{cylinder}} = \frac{m_{\text{liquid, cylinder}}}{V_L}}
\]