Since P(X = x) = 0.3 for all 0 ≤ x ≤ α, we have
[tex]\displaystyle\int_{-\infty}^\infty P(X=x)\,\mathrm dx=1\implies0.3\int_0^\alpha\mathrm dx=0.3\alpha=1\implies\alpha=\dfrac{10}3[/tex]
So,
[tex]P(X>2) = \displaystyle\int_2^\infty P(X=x)\,\mathrm dx=0.3\int_2^{\frac{10}3}\mathrm dx[/tex]
[tex]P(X>2)=0.3\left(\dfrac{10}3-2\right)=\boxed{\dfrac25}[/tex]
