Distribution function is given
$$D(x)= \begin{cases}0, \text{ if } x<0 \\ \frac{x}{5}+\frac{1}{5} \text{ if } 0 \leq x <3 \\ 1, \text{ if } x \geq 3 \end{cases}$$
We need to find $D_1$ - discrete distribution function and $D_2$ - continuous distribution function that equation $$D=p D_1+(1-p)D_2$$ will be correct with chosen $p\in(0,1).$
So I think continuous distribution function should be found $D_2= D'(x)$, but how to find discrete distribution function and find p?