Предмет: Математика, автор: kseniaivanova11

Вы мне можете кто-нибудь ее решить? БУДУ БЛАГОДАРНА))) дам 29 баллов

Среди 16 карандашей четыре красных, а остальные — черные. Какова вероятность того, что среди трех карандашей, взятых случайным образом, хотя бы один будет красным?

Ответы

Автор ответа: Rechnung

$16-4=12\\\\ P(A)=1- \frac{C_{12}^3}{C_{16}^3}=1- \frac{10*11*12}{14*15*16}=1- \frac{11}{28}= \frac{17}{28}$

Интересные вопросы

Предмет: Английский язык, автор: MrReizer

Ребят помогите пожалуйста, буду благодарен
Match 1-5 with a-e to make questons. Then answer the questions.
1. Do you wear...
2. Do you go...
3. Do you...
4. Do you eat...
5. Do you decorate...
a. ... special food on New Year`s Eve?
b. ... to church at easter?
c. ... a costume at Hallowe`en?
d. ... the house at Cristmas?
e. ... presents to your family on Boxing Day?
Если можно пожалуйста дайте ответы

2 года назад

Предмет: Другие предметы, автор: rbhfhggjg

оживление неодушевленных предметов было свойственно человеку во все времена Придумай свои примеры оживления неживых предметов

2 года назад

Предмет: Английский язык, автор: dashashasha11

Даю 62 балла ! Написать краткий пересказ текста , элементарные приложения 7-10 шт !
The use of mobile phones and video games machines is prohibited in most UK schools and some do not allow pupils to bring them through the gates. Others allow pupils to carry phones if they do not use them during the school day, and most expect electronic equipment to be put away at the start of each lesson. Schools are afraid that phones could be lost or stolen and that pupils will interrupt lessons. Schools also worry about misuse of the technology and point to several cases of videos of teachers being placed on the Internet and of pupils bullying by text messages. Modern mobiles are so small that children can use them under their desks to text each other instead of concentrating on the lesson. But one head teacher thinks that prohibiting mobile phones in schools is wrong. He thinks that schools should be making the most of modern technology. He gives the example of a student who used his phone to take a photo of the homework written on the board instead of copying it into his book. The phone was taken away from the pupil. This particular head teacher thinks that this is a mistake and claims that it is more important for pupils to use the latest technology than learn dates in history. In his opinion, we should use in class the good things that mobile phones can offer audio and video technology and access to the Internet. In some schools, children have been given handheld computers with phone and Internet access to use in lessons. In these schools, teachers have reported very little misuse. The students see the smart phones as something useful for class and homework and so they look after them.