Two balls are to be pulled from a vase that contains 7 red balls 9 green balls and 2 black balls. After the first ball Is drawn,

Question

umka2103 [35]

3 years ago

12

Two balls are to be pulled from a vase that contains 7 red balls 9 green balls and 2 black balls. After the first ball Is drawn,

it is not the replaced. What is the probability that two black balls are chosen from the vase?

Mathematics

1 answer:

Vladimir79 [104] · Answer 1 · 2022-07-06T22:58:53+03:00

Answer:

$\frac{1}{153}$

Step-by-step explanation:

There are a total of 7 + 9 + 2 = 18 balls in the vase, therefore, when not replacing the first ball, there would be 18 · 17 = 306 ways to pull 2 balls. There are 2 ways to choose the first black ball and then 1 way to choose the second black ball so there are 2 · 1 = 2 ways to choose 2 black balls. Therefore, the probability is 2 / 306 = $\frac{1}{153}$ .