If you are randomly sample one a a time time with replacement from a bag with 8 blue marbles, 7 red marbles,?
and 5 green marbles, what is the probability of obtaining
A blue marble in one draw from the bag?
Three blue marbles in three draws from the bag?
A red, green, and a blue marble in that order in three draws from the bag?
At least 2 red marbles in three draws from the bag?
Because it is done with replacement, each draw is independent.
The probabilities for each draw are:
P(Blue) = 8 / 20 = 2 / 5
P(Red) = 7 / 20
P(Green) = 5 / 20 = 1 / 4
A blue marble in one draw from the bag?
P(Blue)
Three blue marbles in three draws from the bag?
P(Blue) * P(Blue) * P(Blue)
A red, green, and a blue marble in that order in three draws from the bag?
P(Red) * P(Green) * P(Blue)
At least 2 red marbles in three draws from the bag?
The sum of
P(Red) * P(Red) * 1.0 {first two red, third can be anything}
P(Red) * (1 - P(Red)) * P(Red) {first is red, 2nd is not red, and the 3rd is red}
(1 - P(Red)) * P(Red) * P(Red) {first is not red, 2nd is red, and the 3rd is red}
Ragga ragga - Red Plastic Bag
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£19.99
