h = - 16t^ 2 + 80
[tex]h=-16t^2\text{ + 80}[/tex]The balloon will hit the ground when the height = 0
[tex]\begin{gathered} 0=-16t^2\text{ + 80} \\ \text{collect like terms} \\ \\ 16t^2\text{ = 80} \\ \text{Divide both sides by 16} \\ t^2\text{ = }\frac{80}{16} \\ t^2\text{ = 5} \\ t\text{ =}\sqrt[]{5} \\ t\text{ = 2.236} \\ t\text{ = 2.24} \end{gathered}[/tex]The correct option is B = 2.24
