Solve the Standard Minimization Problem Using Duality $c = 0.3 s + 0.5 t$

Short Answer

Solve the standard minimization problem using duality.
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Minimize $c = 0.3 s + 0.5 t$ ​
subject to $$\begin{array} { l } 0.2 s + 0.1 t \geq 1 \\0.15 s + 0.3 t \geq 1.5 \\10 s + 10 t \geq 80 \\s \geq 0 , t \geq 0\end{array}$$ ​ $c =$ __________
​ $s =$ __________
​ $t =$ __________