The probability is 728/4485.
Setting up combinations for this, we have:
[tex]\frac{_{12}C_5\times_{15}C_3}{_{27}C_8}
\\
\\=\frac{\frac{12!}{5!7!}\times\frac{15!}{3!12!}}{\frac{27!}{8!19!}}
\\
\\=\frac{792\times455}{2220075}=\frac{360360}{2220075}=\frac{728}{4485}[/tex]
