номер 6, страница 65 - гдз по английскому языку 7 класс рабочая тетрадь Hardy-Gould, Mellersh

6 Read the text. Then do the problems.

A French mathematician (Laplace) made this equation:

When we throw a die, there are six possible outcomes: 1, 2, 3, 4, 5, 6. There are three ways of getting an even number: 2, 4, 6.

The probability of getting an even number is the number of ways of getting an even number divided by total number of possible outcomes = 3/6. Or we can say ½, 0.5 or 50%.

1 Imagine you write the months of the year on twelve pieces of paper and put them in a bag. Then you think of a month and, without looking, take a piece of paper from the bag. What is the probability that you pick the month you thought of?

a 1/6 b 1/12 c 4/12

2 If you write the letters of the word millionaire on eleven different pieces of paper and put them in a bag, what is the probability that you will take out a letter i? (Remember: How many letters are there in total? How many letters i are there?) Write the equation.

Choosing a letter i =

Talking about probability

When we make predictions, we say how probable a thing is. Probability is saying how likely (probable) something is to happen (the outcome). Probability can be used to predict the result when throwing a die or tossing a coin. We can say we think it is likely or unlikely to rain tomorrow. We can say it is impossible for pigs to fly. We can say we are certain to pass an exam.

But there is a problem. Words like unlikely and probable can mean different things to different people. Their meaning is not fixed. We might not be sure of what the person means. So, we need to be clearer when we talk about an outcome.

Mathematicians wanted to make how we talk about probability more scientific. They used numbers. They decided that the probability of an outcome can be between 0 (impossible) and 1 (certain). It can be a fraction, decimal or percentage. So an even chance can be expressed as ½, 0.5 or 50%.

1. Представьте, что вы пишете названия месяцев года на двенадцати листках бумаги и кладете их в мешок. Затем вы загадываете месяц и, не глядя, достаете из мешка листок бумаги. Какова вероятность того, что вы вытащите месяц, который вы загадали?

а 1/6

б 1/12

в 4/12

Ответ:

б 1/12

There are 12 months in a year, so there are 12 pieces of paper in the bag (total number of possible outcomes). I think of only one specific month (the number of ways the outcome can happen). Therefore, the probability of picking the month I thought of is 1 out of 12, or 1/12.

В году 12 месяцев, значит в мешке 12 листков бумаги (общее число возможных исходов). Я загадываю только один конкретный месяц (число способов, которыми может произойти исход). Следовательно, вероятность вытащить тот месяц, который я загадал, составляет 1 из 12, или 1/12.

2. Если вы напишете буквы слова 'millionaire' на одиннадцати разных листках бумаги и положите их в мешок, какова вероятность того, что вы вытащите букву 'i'? (Помните: Сколько всего букв? Сколько букв 'i'?) Запишите уравнение. Вероятность вытащить букву 'i' = ______

Ответ:

Choosing a letter i = 3/11

The word "millionaire" has 11 letters in total. The letter "i" appears 3 times. So, the probability of picking the letter "i" is the number of "i"s divided by the total number of letters, which is 3/11.

В слове "millionaire" всего 11 букв. Буква "i" встречается 3 раза. Значит, вероятность вытащить букву "i" - это количество букв "i" поделенное на общее количество букв, то есть 3/11.