Mrs. Sue please help me!
7. A bag contains 7 green marbles, 9 red marbles, 10 orange marbles, 5 brown marbles, and 10 blue marbles. You choose a marble, replace it, and choose again. What is P(red, then blue)? (1 point)
seventy-seven over one hundred sixty-four
nineteen over forty-one
ninety over one thousand six hundred eighty-one
forty-five over forty-one
To find the probability of choosing a red marble followed by a blue marble, you need to calculate two probabilities: the probability of choosing a red marble and the probability of choosing a blue marble after replacing the first marble.
The probability of choosing a red marble is given by the ratio of the number of red marbles to the total number of marbles:
P(red) = number of red marbles / total number of marbles
= 9 / (7 + 9 + 10 + 5 + 10)
= 9 / 41
Since you replace the first marble before choosing the second one, the probability of choosing a blue marble is the same as the probability of choosing a red marble:
P(blue) = number of blue marbles / total number of marbles
= 10 / (7 + 9 + 10 + 5 + 10)
= 10 / 41
To find the probability of both events occurring, you multiply the two probabilities together:
P(red, then blue) = P(red) * P(blue)
= (9 / 41) * (10 / 41)
= 90 / 1681
Therefore, the probability of choosing a red marble followed by a blue marble is 90/1681.