The coefficients a, b, c in the quadratic equation a x^2+ b x+ c =0 are chosen from the set {1, 2, 3, 4, 5, 6, 7, 8}. The probability of this…

The coefficients $\displaystyle \mathrm{a}, \mathrm{b}, \mathrm{c}$ in the quadratic equation $\displaystyle \mathrm{a} x^2+\mathrm{b} x+\mathrm{c}=0$ are chosen from the set {$\displaystyle 1$, $\displaystyle 2$, $\displaystyle 3$, $\displaystyle 4$, $\displaystyle 5$, $\displaystyle 6$, $\displaystyle 7$, $\displaystyle 8$}. The probability of this equation having repeated roots is :