Math problem 17 to detail the process, thank you 5

As can be seen from the figure, there are 50 people who choose **1, 150 people who choose **2, and 100 people who choose **3.

1) The probability of getting a discount of not less than 300 yuan, that is, the number of people who choose **two and **three:

2) Since six people are selected by stratified sampling, there are 1 person who chooses **1, 3 people who choose **2, and 2 people who choose **3.

Among these six people, all events that randomly choose two people are: 6 * 5 = 30 All events with the same discount for two people are: 3 + 1 = 4 so the probability is: 4 30 = 2 15

Hopefully, thank you!

A total of 50 + 150 + 100 = 300 people participated in the promotion.

The probability of choosing ** one is 50 300 = 1 6

The probability of choosing ** two is 150 300 = 1 2

The probability of choosing three is 100 300 = 1 3

1) The probability of getting a preferential amount of not less than 300 yuan is the probability of **two plus **three.

i.e. 1 2 + 1 3 = 5 6

2) If stratified sampling is adopted, 1 person will be selected from **1, 3 people from **2, and 2 people from **3.

There are a total of 6 * 5 2 = 15 draws from 6 people.

At the same time, there are 1z kinds of **two, and there are 3 kinds of **three at the same time.

Then the probability is (1+3) 15=4 15

Solution: p(**1)=50 300=1 6p(**2)=150 300=1 2

p(**3）=100/300=1/3

1): Therefore, the probability of not less than 300 yuan discount p=p(**2)+p(**3)=5 6

2) From the question to know **1, **2**3 will be drawn for 1, 3 people, and 2 people respectively.

Therefore, the probability of drawing 2 people to get the same discount p=(3+1) 15=4 15

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The answer is uploaded in detail.

The point is to derive EF BF, and the rest is simple.

From the slope, we can know that bc ac=, bc=3, and then the Pythagorean theorem can find ab

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According to the meaning of the title, 2a-3+(5-a)=0

a=-25-a=5-（-2）=-7

Therefore m is (-7) (7) = 49