Answer:
There are a total of 3+4+2=9 marbles in the bag
Step-by-step explanation:
All of the outcomes must add up to 1 . Therefore, the probability of NOT drawing a red marble is the same as one minus the probability of drawing a red marble:
P(Not red) = 1 - P(red)
P(Not red) = 1 - P(red)Since there are a 3 marbles:
P(Not red) = 1 - 3/9 = 6/9 = 2/3
So the probability of Not drawing a red marble is 2/3
An alternative approach would be to see that:
P(red) + P(white) + P(blue) = 1
P(red) + P(white) + P(blue) = 1P(white) + P(blue) = 1 - P(red)
Therefore:
P(Not red) = 1 - P(red) = P(white) = P(blue)
