If $\alpha \text{ and }\beta $are roots of the equation $3{{x}^{2}}+5x-2=0$. Find the value of $\tfrac{1}{\alpha }+\tfrac{1}{\beta }$.(A)  $-\tfrac{5}{2}$  (B)  $-\tfrac{3}{2}$  (C)  $\tfrac{1}{2}$  (D)$\tfrac{5}{2}$