Question

монету бросают трижды. какова вероятность того ,что орел выпадет не более 2х раз

Answer 1

это дерево составлять можно

например:орел может может выпасть в 4 случаях,либо 1 раз,либо 2 раза,либо 3 раза,либо вообще не выпасть

получается 2/3 чтоли

Answer 2

Calculating the Probability of Getting Heads 2 or Fewer Times

To calculate the probability of getting heads 2 or fewer times when a coin is tossed three times, we need to consider all the possible outcomes.

There are a total of 2^3 = 8 possible outcomes when tossing a fair coin three times. These outcomes are:

- HHH (3 heads) - HHT (2 heads, 1 tail) - HTH (2 heads, 1 tail) - THH (2 heads, 1 tail) - HTT (1 head, 2 tails) - THT (1 head, 2 tails) - TTH (1 head, 2 tails) - TTT (3 tails)

Out of these 8 outcomes, we need to find the probability of getting 2 or fewer heads. This includes the outcomes with 0, 1, or 2 heads.

Let's calculate the probability step by step:

1. Probability of getting 0 heads: - There is only one outcome with 0 heads: TTT. - Therefore, the probability of getting 0 heads is 1/8.

2. Probability of getting 1 head: - There are three outcomes with 1 head: HTT, THT, and TTH. - Therefore, the probability of getting 1 head is 3/8.

3. Probability of getting 2 heads: - There are three outcomes with 2 heads: HHT, HTH, and THH. - Therefore, the probability of getting 2 heads is 3/8.

To find the probability of getting 2 or fewer heads, we add the probabilities of getting 0, 1, and 2 heads:

1/8 + 3/8 + 3/8 = 7/8.

Therefore, the probability of getting heads 2 or fewer times when a coin is tossed three times is 7/8.