I'm new to linear programming and can't wrap my head around something.Let P be a LP in standard form$$\begin{array}{ll} \text{maximize} & t x\\ \text{subject to} & r x \leq s\\ & x \geq 0\end{array}$$I figured that the dual program is$$\begin{array}{ll} \text{minimize} & s y\\ \text{subject to} & r y \geq t\\ & y \geq 0\end{array}$$However I'm unsure how to find what is a feasible solution for P and not for D and vice versa. Intuitively, if $s$ is positive P should have a feasible solution, but that seems to be wrong and/or incomplete as an answer.
basic linear programming - how to find feasible solutions
linear programming