Suppose you choose a marble from a bag containing 3 red marbles, 5 white marbles, and 4 blue marbles. You return the first marble to the bag and then choose again. Find P (red and blue).

P(red and blue) = 1/12

Step-by-step explanation:

A probability is the number of desired outcomes divided by the number of total outcomes.

Probability of independent events:

If two events, A and B, are independent, the probability of both happening is the multiplication of the probabilities of each event happening, that is:

P (red and blue).

Probability of choosing a red marble, then a blue marble. The marbles are replaced, so the trials are independent.

Probability of a red marble:

3 out of 3 + 5 + 4 = 12. So

Probability of a blue marble:

4 out of 12, so:

P (red and blue).

So

P(red and blue) = 1/12

7.25

step-by-step explanation:

we know that 7 equals to 7.0. we also know that 1/4=0.25. so we can add the two together and we get 7.25

answer: 7 x 2/5 = 2.8 hours, is your answer. your welcome! : 3

step-by-step explanation: first work out how long it took to hose 1/7 of the lawn which is 2/5 hours. times that by 7 to get the whole lawn.

sorry i don't know the other answer. i didn't learn what a proportional relationship is.