The cost of the TV is given as $350.
The cost of the TV after a discount of 20% is applied, is calculated as,
[tex]\begin{gathered} \text{ Final Cost=(1-}\frac{\text{ Discount Percent}}{100}\text{)}\times\text{ Initial Cost} \\ \text{ Final Cost=(1-}\frac{\text{ 2}0}{100}\text{)}\times350 \\ \text{ Final Cost=(}\frac{80}{100}\text{)}\times\text{ 3}50 \\ \text{ Final Cost=}280 \end{gathered}[/tex]Thus, the final cost of the TV is $280.
Therefore, option B is the correct choice.
