Question

Есть ручки четырёх разных цветов: синего, чёрного, красного и зелёного. Наугад выбирают две ручки. Какая возможность того, что: 1) одна с них синего цвета, а вторая - чёрного цвета; 2) сред избранных есть ручка зелёного цвета?

Answer 1

Всего 4 ручки, а 4 ручки здесь это-100%
Значет надо:
100:4=25%
Ответ: 25%(этот ответ подходит к 1 вопросу и к 2 вопросу)

Answer 2

Probability of selecting one blue pen and one black pen

To calculate the probability of selecting one blue pen and one black pen, we need to determine the total number of possible outcomes and the number of favorable outcomes.

The total number of possible outcomes is the number of ways we can choose two pens from a set of four. This can be calculated using the combination formula:

Total number of possible outcomes = C(4, 2) = 4! / (2! * (4-2)!) = 6

Now, let's determine the number of favorable outcomes, which is the number of ways we can choose one blue pen and one black pen. We have two blue pens and one black pen, so the number of favorable outcomes is:

Number of favorable outcomes = 2 * 1 = 2

Therefore, the probability of selecting one blue pen and one black pen is:

Probability = Number of favorable outcomes / Total number of possible outcomes = 2 / 6 = 1/3

So, the probability that one pen is blue and the other is black is 1/3.

Probability of selecting a green pen among the chosen pens

To calculate the probability of selecting a green pen among the chosen pens, we need to determine the total number of possible outcomes and the number of favorable outcomes.

The total number of possible outcomes is the number of ways we can choose two pens from a set of four, which we have already calculated as 6.

Now, let's determine the number of favorable outcomes, which is the number of ways we can choose one green pen among the chosen pens. Since we have only one green pen, the number of favorable outcomes is either 1 or 0, depending on whether a green pen is chosen or not.

Therefore, the probability of selecting a green pen among the chosen pens is:

Probability = Number of favorable outcomes / Total number of possible outcomes = 1 / 6

So, the probability that one of the chosen pens is green is 1/6.

Please let me know if there's anything else I can help you with!