Respuesta :
Answer:
simple - 1/21 chance
Step-by-step explanation:
since its asking for the probability of "a" marble, and not all the green marbles, you add everything up and slap what outcome (1 in this case) on top of the 21
here is cat

Answer:
3 is for green marbles
21 is the total of all marbles
Step-by-step explanation:
you only have 1 event so I think we don't need some formula or something
the formula is this if the event A and B has no intersection P( A U B)= P(A)+P(B)
and if it has intersection, the formula is like this P( A ∩ B)=P(A)+P(B)-P( A ∩ B)
