Answer:
[tex]\boxed{\sf \dfrac{14}{95}}[/tex]
Explanation:
Black ribbons = 8 ribbons
Green ribbons = 12 ribbons
Total ribbons: 12 + 8 = 20 ribbons
[tex]\sf Probability = \dfrac{Favorable \ Outcomes}{Total \ Possible \ Outcomes}[/tex]
For Lila:
[tex]\sf Lila \ picks \ black \ : \ \dfrac{8}{20}[/tex]
Left black ribbons: 8 - 1 = 7 black ribbons
Left total ribbons: 20 -1 = 19 total ribbons
For Jessica:
[tex]\sf Jessica \ picks \ black \ : \ \dfrac{7}{19}[/tex]
Probability that they both pick black ribbons:
[tex]\sf \rightarrow \dfrac{8}{20} \ x \ \dfrac{7}{19}[/tex]
[tex]\sf \rightarrow \dfrac{14}{95}[/tex]