Xiaoming's home is close to the railway station. He can get up according to the bell of the station building every day. Every time the clock in the station room rings, there is a delay of 3 seconds, and it rings again after an interval of 1 second. If Xiao Ming wakes up from the first bell, how many seconds has passed before and after 6 am? 1. There are two roads from A to B, four roads from B to C, and three roads from A to C without B, so there are different roads from A to C. There are 3, 5 and 2 students in Class A, Class B and Class C respectively. We are going to choose two students from different classes. * * * There are different selection methods. 3. Choose two students from A, B and C to take part in an activity on a certain day. One student will take part in the morning activity and the other will take part in the afternoon activity. There is a different choice. 4. From the four letters A, B, C and D, take out three letters at a time and arrange them in a row. * * * There are different arrangements. If four volunteers are selected from six volunteers to do four different jobs: translation, tour guide, shopping guide and cleaning, there are different schemes. 6.A, B, C, D and E * * *, there are shuttle buses at all five railway stations, so it is necessary to prepare train tickets between stations. 7. In a certain year. Each team will play a game with each other at home and away, playing a game of * * *. 8. Numbers 1, 2, 3, 4, 5, 6 can form a positive integer, and there are no duplicate numbers. 9. The number 10 can form a three-digit number from 0 to 9, and there is no duplicate sign. (2) There are five different books, and I want to buy three books for three students, each 1. * * There is a different selection method. 1 1. It is planned to exhibit 10 different paintings, including watercolor painting 1 painting, 4 oil paintings and 5 Chinese paintings, which will be exhibited continuously. (2) Arrange 18 people in two rows, with 9 people in each row, with different arrangement methods; (3) Arrange three rows of 18 people, with 6 people in each row. There are different arrangements. 65,438+03.5 people stand in a row, (65,438+0) where A and B must be adjacent and arranged differently. (2) A and B cannot be adjacent, so they have different arrangements; (3) There are different arrangements that Party A does not stand in the front row and Party B does not stand in the back row. 14.5 Students take photos with 1 teacher, and the teacher can't stand in the front row or the back row. * * There is a different arrangement. 15.4 Students and three teachers take pictures continuously, but teachers can't stand at both ends. And there are different ways for teachers to line up together. 16. There are 7 parking spaces in the parking lot, and now there are 4 cars to park. If you want to connect these three spaces together, there are several ways to park. 17. Select 4 athletes to form a relay team to participate in the 4× 100 meter race. Then there are three arrangements, in which Party A and Party B don't run two sticks in the middle. 18. A pocket contains 7 white balls and 1 black balls of the same size. (1) Take out three balls from your pocket. * * * There is a way. (2) Take three balls out of the pocket to make them contain 1 black ball, and take them properly; (3) Take three balls out of your pocket so that they don't contain black balls. There is a way to take them away. 19. Four football teams, A, B, C and D, play a single round-robin match: (1) * * A venue is needed; (2) It may be the champion and runner-up. 20. According to the following conditions, there are different ways to choose 5 people from 12. (1) A, B and C must be selected; (2) Party A, Party B and Party C cannot be elected; (3) A must be selected, but B and C cannot be selected; (4) Only one of Party A, Party B and Party C was elected; (5) A, B and C, with a maximum of two people; (6) Party A, Party B and Party C were elected at least 1; 2 1. A song and dance troupe has seven actors, three of whom can sing, two can dance, and two can both sing and dance. Now we have to choose two of the seven actors, one singing and the other dancing, and go to the countryside to perform. What is the choice? 22. Choose three boys and two girls from six boys and m-girls to undertake A, B and C respectively. * * * There are different distribution methods. Mathematics examination paper and answer 1. Multiple choice questions (this question * * 10 is a minor question, with 4 points for each minor question, out of 40 points) 1. The following operations are correct: () A.4 = 2b.2-3 =-6 C.X2X3 = X6. In recent years, the number of people learning Chinese all over the world has been increasing. It is reported that in 2006, the number of students studying Chinese overseas reached 38.2 million. It is expressed by scientific notation as () person (with three significant digits reserved) A.0.382×10b.3.82×10c.38.2×10d.382×103, as shown in the figure, the top view of the regular quadrangle is Isosceles, triangles, circles and diamonds can be placed at will, with the graphics facing down, and any card can be opened. If the opened graph is axisymmetric, it can pass the test, and the probability of passing the test once is () A.B.C.D.5, as shown in the figure, the diameter CD⊙O passes through the midpoint G of the chord EF, and ∠ EOD = 44. Then ∠DCF is equal to () A.22B.44C.46D.886. Three students, A, B and C, take part in the kite competition. The length of the kite line and the angle between the line and the ground are shown in the following table (assuming that the kite line is straight, ignoring the height of the three students). Then, among the kites released by the three people, (a) the kite released by students A, B and C has a line length of 100 m, and the angle between the line and the ground is 40 45 60 a. The highest B.C. is the highest C.B., the lowest D.C. is the lowest 7. The state implements the policy of "two exemptions and one subsidy" for students in the nine-year compulsory education stage. The following table shows some free textbook subsidies provided by a middle school in our city. 1989 The total free subsidy per person is (yuan) 1 10 90 50 (person) 80 300 (yuan) 4000 26200. If you want to know the data in the blank, you can set the number of students in grade seven as X, and the number of students in grade eight as Y. According to the meaning of the question, the system of equations is () A.B.C.D.8 Put six equal circles together in three forms: A, B and C, so that two adjacent circles circumscribe each other, and the connecting lines as shown in the figure form regular hexagon, parallelogram and regular triangle respectively. Write the sum of the areas of the six sectors (shaded parts) outside the center line as S, P, Q, then () 1 1, factorization: = 12, as shown in the figure, △OP A and △A P A are isosceles right triangles, and there are points P and P on the image with function y=, and the hypotenuse OA. It is known that the side length of the diamond ABCD is 4㎝, ∠ a = 60, the arc BD is the arc with the center and the radius b, and the arc CD is the arc with the center and the radius b, then the area of the trademark pattern is _ _ _ _ _ _ _.14,2000. Farmers only need 10 yuan each year to enjoy cooperative medical care. The reimbursement methods for hospitalization expenses are as follows: the reimbursement ratio of hospitalization expenses (%) shall not exceed 3,000 yuan,153,000-4,000 yuan, 254,000-5,000 yuan and 305,000-10000 yuan. If someone reimburses 880 yuan's hospitalization expenses, then the hospitalization expenses will be _ _ _ _ _ _ _ yuan. Newcomers teach seventh-grade mathematics next semester (3) final exam questions. 1. Fill in the blanks: 1, point B is on the Y axis, above the origin, and 4 units away from the origin, then the coordinate of this point is; 2. If the arithmetic square root of a number is 8, then the cube root of this number is; Question 4: Figure 3, as shown in the figure, BE bisects ∠ABD, CF bisects ∠ACD, BE and CF satisfy g, if ∠ BDC = 140, ∠ BGC =10, then ∞. According to the measurement results marked in the figure, it is found that the degree of ∠A is _ _ _ _ _ .6, the square roots of a positive number X are 2a 3 and 5 a, then A is _ _ _ _ _ _ _ .7, and if X+2Y+3Z = 10, 4x+3Y. Then the value of x is _ _ _ _ _ _ _ _ .9, and it is known that AD is the midline on the BC side of ABC, AB= 15cm, AC= 10cm, so the circumference of ABD is longer than that of ABD _ _ _ _ _ _ _ _ _ .6544 Then the degree of each inner angle of this triangle is _ _ _ _ _ _ _ _. 1 1. If it is known that the sum of the inner and outer angles of a polygon is * * * 2 160, then the number of sides of this polygon is _ _ _ _ _ _ _ _. Then the coordinate of point A is. 13, and it is known that every external angle of a polygon is equal, and the sum of internal angles is twice the sum of external angles, so every external angle is equal to 1. Fill in the blanks (65438+ 0.5 for each question, * * 15) 1: A point outside the straight line is called a point pointing to the straight line. 2. Axiom of parallel lines. 3. Conditions of parallel lines: . 4. The essence of parallel lines: . The sum of the external angles of the 5:n polygon is; The sum of internal angles is. 6. An N-sided polygon can make a diagonal line from one of its vertices, which divides the polygon into three triangles. 7. Starting from an equation in binary linear equations, this method is called substitution method for short. 8. The coefficients of the same unknown in two equations are simply called addition and subtraction. 9: For 2x-y=3, we have a formula to indicate that y is:. 10: For four pieces of 10cm, 7cm, 5cm and 3cm, three pieces are selected to form a triangle, and the circumference of the triangle is. Second, the solution and application 1, as shown in Figure 1, is the rest of a trapezoidal iron sheet. What are the other two corners of the trapezoid? (4 points) 2. As shown in figure ②, a//b, c and d are cutting lines, 1=80, 5=70. What are the degrees of 2, 3 and 4 respectively? Why? (6 points) 3. Mark the following points in the plane rectangular coordinate system: point A is on the Y axis, above the origin, and 2 unit lengths away from the origin; Point B is on the X axis, on the right side of the origin, and is 1 unit length away from the origin; Point C is on the X axis and on the right side of the Y axis, and the distance between every two coordinate axes is 2 unit lengths; Point D is on the X axis, located on the right side of the origin, and 3 unit lengths away from the origin; Point E is located above the X axis and to the right of the Y axis, 2 unit lengths away from the X axis and 4 unit lengths away from the Y axis. Connect these points in turn. What do you think it looks like? (8 points) 4. As shown in Figure ③, the coordinates of point A and point B in triangle AOB are (2,4) and (6,2) respectively. Find the area of triangle AOB (hint: the area of triangle AOB can be regarded as the area of a rectangle minus the area of some small triangles). (8 points) 5. Calculate the degree of each inner angle of a regular pentagon and a regular decagon. (5 points) 6. The sum of the inner angles of a polygon is equal to 1260. How many polygons does it have? (5 points) 7. As shown in Figure 4, 1 = 2, 3= 4, A= 100, find the value of x. (6 points) 8. Solve the following equation (***8 points) (1) x+2y = 9 (2) 2x-y = 53x-2y =-13x+4y = 2iii as required. The application of binary linear equations (7 points per question, * * 33. The sales ratio of a disinfectant in large bottles (500g) and small bottles (250g) is 2: 5. A factory produces 22.5 tons of this disinfectant every day. How many bottles should these disinfectants be divided into large bottles and small bottles? 2. Two big harvesters and five small harvesters work for 2 hours to harvest wheat. 6 hectares, 3 big harvesters and 2 small harvesters harvest 8 hectares of wheat in 5 hours. 1 hour 1 NTU harvester and 1 small harvester harvest how many hectares of wheat? 3. The route from city A to city B is 1200km long. It takes 2 hours and 30 minutes for the plane to fly from A to B, and 3 hours and 20 minutes to fly from B to A against the wind. Find the average speed and wind speed of the plane. 4. Make tin cans with tin foil. Each tinplate can be made into 25 boxes or 40 boxes. A box body and two box bottoms form a set of boxes. At present, there are 36 sheets of iron. How many sheets are used to make the box, and how many sheets can make the box and the bottom just match? 5. It is necessary to use 30% and 75% of seed preservatives and 50% of antiperspirant to prepare 18kg preservative. How much do I need to take each of the two potions?