A jar has 25 red, 15 blue and 10 green marbles. Drawing 3 marbles all at once what is the probability of drawing 2 red and 1 blue? 2 red? Not sure if this is right.

For the fist problem I multiplied (25/50)*(24/49)*(15/48)=.0765
and for the next problem I multiply (25/50)*(24/49)*(25/48)=.128

If multiplication is right for first question, I agree.

Second question not completely stated. if for 2 red and either blue or green, then it is right.

To find the probability of drawing 2 red and 1 blue marble, you need to calculate the probability of each event happening and then multiply them together.

1. Calculate the probability of drawing a red marble on the first draw:
There are 25 red marbles out of a total of 50 in the jar, so the probability of drawing a red marble on the first draw is 25/50.

2. Calculate the probability of drawing a red marble on the second draw, given that the first marble was red:
After one red marble has been removed, there are now 24 red marbles left out of a total of 49 remaining marbles. Therefore, the probability of drawing another red marble on the second draw is 24/49.

3. Calculate the probability of drawing a blue marble on the third draw, given that two marbles drawn previously were red:
After the two red marbles have been removed, there are now 15 blue marbles left out of a total of 48 remaining marbles. Hence, the probability of drawing a blue marble on the third draw is 15/48.

Now, multiply these probabilities together to get the overall probability of drawing 2 red and 1 blue marbles:
(25/50) * (24/49) * (15/48) ≈ 0.0765

Therefore, your calculation for the first question is correct.

To find the probability of drawing 2 red marbles, you follow the same steps, but in the last step, you calculate the probability of drawing another red marble instead of a blue one.

1. Calculate the probability of drawing a red marble on the first draw: 25/50.
2. Calculate the probability of drawing a red marble on the second draw, given that the first marble was red: 24/49.
3. Calculate the probability of drawing a red marble on the third draw, given that two marbles drawn previously were red: 25/48.

Multiply these probabilities together to get the overall probability of drawing 2 red marbles:
(25/50) * (24/49) * (25/48) ≈ 0.128

Hence, your calculation for the second question is also correct.