1. The following event is an impossible event ().
Xiaoming won the prize in the sports lottery.
B. Throw two cube dice at will, and the sum of points is 1.
C. The sun rises in the east
D. it will rain tomorrow
2. The following events are definite events: (1) Pure water at 20℃ freezes at standard atmospheric pressure; ② Exam at ordinary times 100, Xiaobai105; (3) Throw a coin, and after falling, face up; ④ The area of a rectangle with side lengths A and B is AB. 1。
3. The correct number in the following statement is () ① If something is unlikely to happen, it can't happen; (2) If something is possible, it will happen; If an event cannot happen, it is an inevitable event. A.0B. 1 C.2D.3
4. In the following events, the occurrence probability is greater than 0 and less than 1: (a) the sun rises slowly in the west; (b) Young trees grow tall and slow; (c) downward flow of water; (d) A bridge passes 60 cars in 20 minutes.
5. The event with a probability of 0 among the following events is () A. When you flip a coin, you get a reversal. B. One minute, you walk100km. When you roll the dice, you get a 5. D.there will be a sunrise tomorrow.
6. The following statements are correct: (a) If the probability of an event is one in 100,000, it means that it cannot happen; B) If it is not impossible, it means inevitable; C) Random events may or may not occur; D) If the probability of an event is 99.999%, it means that it will definitely happen.
7. "Almost impossible" in life means () A. Impossible events B. Definite events C. Inevitable events D. Uncertain events
Fill in the blanks (***4 small questions, out of 24 points)
8.(2006? Wenzhou), as shown in the figure, is a square schematic diagram made up of eight identical isosceles right-angled triangular black and white tiles. An ant crawls freely on it and stays on the tile randomly. The probability of ants staying on black tiles is _ _ _ _ _ _ _.
9. Basketball shot just hit, belonging to _ _ _ _ _ _ _ _ event. Under normal circumstances, water naturally flows from the lower part to the higher part, which is a _ _ _ _ _ _ _ event.
10. Xiaoying bought a box of apples from the fruit market. After unpacking, she found that five apples were rotten. This is the _ _ _ _ _ _ _ event.
1 1. The following events: (1) It will be fine tomorrow; (2) Xiaoming's younger brother is younger than Xiaoming; (3) Brazil and Turkey played a football match, and Brazil won; The sun goes around the earth. The uncertain event is _ _ _ _ _ _ _.
Third, answer questions (***6 small questions, out of 43 points)
12. A shopping mall held a shopping prize-winning activity, and the goods with the value of 50 yuan could be drawn once. Lily spent 120 yuan shopping in the mall and won two lottery tickets as required. As a result, one of them won the prize. Can it be said that the winning rate in the shopping mall lottery is 50%? Why?
13. The probability of beer bottle cap "opening" when it is thrown to the ground is studied through experiments. What do you think of the following statement? what do you think? (1) Some students said that after I had done ten experiments, I opened my mouth up three times, and it was concluded that the probability of opening the bottle cap up after landing was about 30%. (2) The beer bottle cap used by a classmate accidentally rolled away, and another classmate suggested that you can change it into a coke bottle cap to continue the experiment; (3) Some students say that the speed of using a bottle cap is too slow. If five beer bottles of the same model are thrown at the same time, each throwing is equivalent to throwing a bottle cap five times, which can improve the testing speed.
14. There are five bags and five wishes, and the bags contain balls of the same size. Quantity, color and desire are shown in the table below. Please find a bag for each wish, so that these wishes are the most promising: the bag can hit the ball, and the wish (1) 1 red ball. 19 white ball a, want to take out a yellow ball (2)20 red balls b, want to take out a green ball (3) 10 red ball, 10 green ball c, want to take out a white ball (4) 10 red ball,/kloc-0 1 green ball E. I want to take out a white ball and a green ball 15. Put some glass balls that are the same except for different colors in three opaque cloth bags and mix them evenly. The details are as follows: 123 color, quantity and type of glass balls: 2 green balls, 2 yellow balls and 5 red balls 65438+. (1) Randomly draw a glass ball in yellow, green or red from the first cloth bag; (2) randomly drawing two glass balls from the second cloth bag, wherein at least one of the two balls is not green; (3) Randomly draw a red glass ball from the third cloth bag; (4) Randomly draw a glass ball from the first bag and the second bag, and the two balls have the same color.
16. A shopping mall has a turntable that can rotate freely, as shown in the figure. It is stipulated that customers can get a chance to rotate the turntable once they have bought 10 yuan. When the turntable stops, where the pointer falls, you can get the corresponding reward. The following table is a set of statistics during the activity: (1) Calculate and complete the table: the number of times the turntable is rotated n100150 200 500 8001000 and the number of times it falls on the pen M 68 165438. 5438+036 345 564 70 1 frequency falling on the pen (2) Please estimate how close the frequency will be when N is large.
17. Xiaoli draws a bar chart according to the average number of five brands of ice cream sold by her uncle every day in the last week: (1) According to Xiaoli's statistical results, please design a purchase plan for Uncle Li. (2) How to determine the total purchase amount and what other factors should be considered?