Two fair dice are thrown. The numbers on them are taken as l and m, and a system of linear equations
$\begin{aligned} & x+y+z=5 \\ & x+2 y+3 z=\mu \\ & x+3 y+\lambda z=1\end{aligned}$
is constructed. If p is the probability that the system has a unique solution and q is the probability that the system has no solution, then :