You randomly draw a marble that contains 3 blue marbles, 4 green marbles, and 5 red marbles.
QUESTION: what is P (draw a blue marble)?

ANSWER!!: 3/12 = 0.25

In cases like this, i.e. when you could pick every marble with the same probability, you compute the probability of picking a specific marble colour by dividing the number of favourable outcomes by the total number of outcomes.

The number of favourable outcomes is 3, because there are 3 blue marbles.

The total number of outcomes is 12, because there are 12 marbles in total.

phosphate, calcium ion, chloride ion, neon atom

step-by-step explanation:

question 1 is 8, question 2 is 9, question 3 is 24

step-by-step explanation:

now, the numbers they give you at the top are the key. from there, you just have to plug and chug! let's try 1, 2, and 3!

key: a=3, b=5, c=6

1. a+5

remember, a=3, so we plug that in to get 3+5=8

2. 15-c

c=6, so we plug that in to get 15-6=9

3. 4b

b=6, so we plug it in to get 4*6=24

time to try the rest on your own! if you put the answers below in a comment, i'll check them for you!