Question

Из урны в которых находятся 12 белых 8черных шаров вынимают 2 шара.Какова вероятность что оба шара будут черными?

Answer 1

Обозначим событие, состоящее в появлении двух черных шаров, через А. Общее число возможных случаев n равно числу сочетаний из 20 элементов (12 + 8) по два: .n=20*19/2=190 Число случаев m, благоприятствующих событию А, составляет 8*7/2=28 По формуле P(A)=m/n,28/190=0,147

Answer 2

Probability of Drawing Two Black Balls from an Urn

To calculate the probability of drawing two black balls from an urn containing 12 white and 8 black balls, we can use the formula for probability:

Probability = (Number of favorable outcomes) / (Total number of possible outcomes)

In this case, the total number of balls in the urn is 12 white + 8 black = 20 balls.

The probability of drawing a black ball on the first draw is 8 black / 20 total balls. After the first draw, there are 19 balls left in the urn, with 7 black balls remaining.

The probability of drawing a black ball on the second draw, given that the first ball drawn was black, is 7 black / 19 total balls.

Therefore, the probability of drawing two black balls in succession is: Probability = (8/20) * (7/19) = 0.147