Question

В классе 26 человек, среди них два близнеца ( андрей и сергей ) класс случайным образом делят на две группы по 13 ч в каждой найти вероятность того, что андрей и сергей окажутся в одной группе???

Answer 1

Это конечно случайность но вероятность есть!/
1*12/25=0,48 

Answer 2

Probability of Andrei and Sergey being in the same group

To find the probability of Andrei and Sergey being in the same group, we need to consider the total number of ways the class can be divided into two groups of 13 students each.

Given that there are 26 students in the class, we can calculate the total number of ways to divide them into two groups of 13 using the combination formula:

Total number of ways to divide the class into two groups of 13 = C(26, 13)

Using the combination formula, we can calculate this as:

C(26, 13) = 26! / (13! * (26-13)!)

Now, to find the number of ways Andrei and Sergey can be in the same group, we need to consider that they are treated as a single entity (since they are twins). So, we have 25 entities to divide into two groups of 13.

Number of ways Andrei and Sergey are in the same group = C(25, 13)

Using the combination formula, we can calculate this as:

C(25, 13) = 25! / (13! * (25-13)!)

Finally, we can calculate the probability by dividing the number of ways Andrei and Sergey are in the same group by the total number of ways to divide the class into two groups:

Probability = (Number of ways Andrei and Sergey are in the same group) / (Total number of ways to divide the class into two groups)

Let's calculate the probability using the given values.