2.
设\(M,N \)为两个随机事件,给出以下命题:
\((1)\)若\(M,N \)为互斥事件,且\(P\left(M\right)= \dfrac{1}{5},P\left(N\right)= \dfrac{1}{4} \),则\(P\left(M∪N\right)= \dfrac{9}{20} \);
\((2)\)若\(P\left(M\right)= \dfrac{1}{2},P\left(N\right)= \dfrac{1}{3},P\left(MN\right)= \dfrac{1}{6} \),则\(M,N \)为相互独立事件;
\((3)\)若\(P\left( \bar{M}\right)= \dfrac{1}{2},P\left(N\right)= \dfrac{1}{3},P\left(MN\right)= \dfrac{1}{6} \),则\(M,N \)为相互独立事件;
\((4)\)若\(P\left(M\right)= \dfrac{1}{2},P\left( \bar{N}\right)= \dfrac{1}{3},P\left(MN\right)= \dfrac{1}{6} \),则\(M,N \)为相互独立事件;
\((5)\)若\(P\left(M\right)= \dfrac{1}{2},P\left(N\right)= \dfrac{1}{3},P\left( \bar{MN}\right)= \dfrac{1}{6} \),则\(M,N \)为相互独立事件.
其中正确命题的个数为 \((\) \()\)