Question

Перед началом первого тура чемпионата по шашкам участников разбивают на игровые пары случайным образом с помощью жребия. Всего в чемпионате участвуют 26 шашистов, среди которым 15 участников из России, в том числе Геннадий Горьков, найдите вероятность того, что в первом туре Геннадий Горьков, будет играть с каким либо шашистом из России.ответ должен быть: 0,56поясните как?

Answer 1

Благоприятное событие - любой участник из России, но не Геннадий Горьков (сам себе соперником не может быть). Их число равно 15-1=14. Общее число исходов равно 26-1=25.
$P(A)= \frac{m}{n} = \frac{14}{25}=0.56$
Ответ: 0,56

Answer 2

Calculating the Probability

To calculate the probability of Gennady Gorkov playing against any Russian chess player in the first round, we need to determine the number of possible pairings that include Gorkov and a Russian player, and then divide it by the total number of possible pairings.

According to the information provided, there are 26 participants in the championship, with 15 of them being from Russia, including Gennady Gorkov. We can assume that the pairings are randomly assigned using a draw.

To find the number of possible pairings that include Gorkov and a Russian player, we can multiply the number of Russian players (15) by the number of non-Russian players (26 - 15 = 11). This gives us a total of 165 possible pairings.

To find the total number of possible pairings, we need to calculate the number of ways to choose 2 players from the total number of participants (26). This can be calculated using the combination formula: C(n, r) = n! / (r!(n-r)!), where n is the total number of participants and r is the number of players in each pairing.

Using this formula, we can calculate the total number of possible pairings as follows:

C(26, 2) = 26! / (2!(26-2)!) = 26! / (2!24!) = (26 * 25) / (2 * 1) = 325

Therefore, the total number of possible pairings is 325.

Now, we can calculate the probability by dividing the number of pairings that include Gorkov and a Russian player (165) by the total number of possible pairings (325):

Probability = Number of pairings with Gorkov and a Russian player / Total number of possible pairings = 165 / 325 = 0.5077

Rounding to two decimal places, the probability is approximately 0.51.

Please note that the probability is approximate because we are assuming that the pairings are randomly assigned using a draw.