Question

В ящике находятся 17 белых и 15 чёрных шаров. найти вероятность того, что. а) наудачу выбранный шарокажется черным б) два на удачу выбранных шара окажутся чёрными

Answer 1

Ответ должен быть буква б

Answer 2

Probability of randomly selecting a black ball

To find the probability of randomly selecting a black ball from the box, we need to calculate the ratio of the number of black balls to the total number of balls in the box.

In this case, there are 17 white balls and 15 black balls in the box. Therefore, the total number of balls is 17 + 15 = 32.

The probability of randomly selecting a black ball can be calculated as:

Probability of selecting a black ball = Number of black balls / Total number of balls

Probability of selecting a black ball = 15 / 32

So, the probability of randomly selecting a black ball is 15/32.

Probability of two randomly selected balls both being black

To find the probability of two randomly selected balls both being black, we need to calculate the ratio of the number of ways to select two black balls to the total number of ways to select two balls from the box.

The number of ways to select two black balls can be calculated as:

Number of ways to select two black balls = (Number of black balls choose 2)

Using the combination formula, we can calculate the number of ways to select two black balls as:

Number of ways to select two black balls = (15 choose 2)

The total number of ways to select two balls from the box can be calculated as:

Total number of ways to select two balls = (Total number of balls choose 2)

Using the combination formula, we can calculate the total number of ways to select two balls as:

Total number of ways to select two balls = (32 choose 2)

Finally, the probability of two randomly selected balls both being black can be calculated as:

Probability of two black balls = (Number of ways to select two black balls) / (Total number of ways to select two balls)

**Probability of two black balls = (