My recent winter holidays were a lot of fun. I tried to visit as many places as I could and to do a lot of different things. Even though the weather wasn't very nice, it didn't make me feel sad. I went to the mall and to the skating-rink with my family and friends. It's always interesting to learn something new, so I also visited the movies and watched some great films. And then, of course, there were New Year and Christmas, which are both my favourite holidays. We had a gorgeous Christmas-tree decorated with toys and Christmas lights. On the first day of new year I got many presents from my family and relatives. After all, it was just great to take some time off from school and to sleep till noon. I really enjoyed my winter holidays.
Играют равносильные шахматисты, поэтому вероятность выигрыша р = 1/2; следовательно, вероятность проигрыша q также равна 1/2. Так как во всех партиях вероятность выигрыша постоянна и безразлично, в какой последовательности будут выиграны партии, то применима формула Бернулли. Найдем вероятность того, что две партии из четырех будут выиграны:
Р4 (2)=C42p2q2 = 4*3/(1*2)*(1/2)2(1/2)2 = 6/16.
Найдем вероятность того, что будут выиграны три партии из шести:
Р6(3)=C63p3q3 = 6*5*4/(1*2*3)*(1/2)3(1/2)3=5/16.
Так как Р4(2)> Р6(3), то вероятнее выиграть две партии из четырех, чем три из шести.
