Answer:
-7/3
Step-by-step explanation:
7,14,21,28,35,42,49,56,63,70,77,84,91,98,105,112,119,126
18,36,54,72,90,108,126
So the first person to get both of them is the 126th person
Gotta see a pic of the paper
(red, green) = (2, 1), (2, 2), (2, 3), (2, 4), (2, 5), (2, 6), (4, 1), (4, 2), (4, 3), (4, 4), (4, 5), (4, 6), (6, 1), (6, 2), (6, 3), (6, 4), (6, 5), (6, 6)
Size of sample space = 18.