Answer
$\displaystyle \frac{1}{15}$
Work Step by Step
$P(E)=\displaystyle \frac{\text{Number of favorable outcomes}}{\text{Total number of outcomes}}=\frac{n(E)}{n(S)}$
$n(S)=C(10,2)=45$
$E$ =(2 of the 3 stocks with $4\%+$ yields) AND (0 of the other 7)
$n(E)=C(3,2)\cdot C(7,0)=3$
$P(E')=\displaystyle \frac{3}{45}=\frac{1}{15}$
