20 12 the math problem in xiaoshengchu, Lanzhou city is the sum and answer.

Fill in the blanks. (3 points for each small question, ***30 points)

(1) In the subtraction formula, the sum of the minuend, subtraction and difference is 360, and the ratio of difference to subtraction is

1∶9, the minuend is (), and the minuend is ().

(2) Two complex numbers A and B are coprime, the number A is greater than the number B, and their least common multiple is 280, the number A..

It is (), and the number B is ().

(3) Among the four scores of,, and, the largest number is () and the smallest number is ().

(4) Two measuring cups, A and B, each containing the same amount of water. After 20 grams of water is poured from Cup A into Cup B, the weight of Cup A is equivalent to that of Cup B, but each cup originally contains () grams of water.

(5) The circumference of a triangle is 46 cm, and the distance from a point P to three sides is 4 cm. The area of this triangle is () square centimeters.

(6) The number of students in Class One and Class Two in Grade Six is equal. The number of boys in class one is the number of girls in class two, and the number of boys in class two is the number of girls in class one. The ratio of the number of girls in Class One and Class Two is ().

(7) Cut a cylindrical wooden stick into several parts from top to bottom along the diameter of its bottom surface, and then make the height of the cylinder into an approximate cuboid with the same volume. It is known that the side area of a cylindrical rod is 75.36 square centimeters, and the width of a spliced cuboid is 4 centimeters. The volume of a cuboid is () cubic centimeters.

(8) The length and width of a piece of cloth are 18. 1 m and 1.6 m respectively. Cut out two right-angled pennants with right-angled sides of 4m and 3m with this cloth, and at most () faces can be cut out.

(9) There are four pastures, the distance from the first pasture to the second pasture is 1.5km, the distance from the second pasture to the third pasture is 10km, the distance from the third pasture to the fourth pasture is 4.4km, and the distance from the fourth pasture to the first pasture is 4. 1km. Then the distance from the first pasture to the third pasture is () kilometers.

(10) The inner diameter of the ring is 5cm and the outer diameter is 6cm. If 100 rings are connected into a chain one by one, the length of the chain after straightening is () cm. (The shape of each ring remains unchanged after straightening)

Second, the correct picture is "√" and the wrong picture is "×". (3 points for each small question, ***6 points)

(1)A, B and C. If A is a multiple of C and B is also a multiple of C, then C must be the greatest common divisor of A and B. ()

(2) A cuboid composed of four small cubes with sides of 1 decimeter may have a surface area of 18 square decimeter or 16 square decimeter. ( )

Third, choose the serial number of the correct answer in (). (4 points for each small question, *** 16 points)

(1) The following four numbers are all five digits, where f = 0 and m is a natural number. Then the number that must be divisible by 3 and 5 is ().

1、MMMFM 2、MFMFM 3、MFFMF 4、MFMMF

(2) Punch out some circles from two square steel plates with equal thickness and length (as shown in the figure, the circles on each plate are the same size). Compared with the weight of the remaining scraps, the following statement is correct ().

1, right 2, right 3, equal right.

(3) If A, B and C are three numbers greater than 0, and A >；; B>c, which of the following is correct?

( )。

1 、>; 1 2 、>; 1 3 、& lt 1 4 、& lt 1

(4) In order to promote sales, shopping malls provide preferential treatment to customers in accordance with the following provisions:

(1), if the shopping does not exceed 200 yuan at one time, there is no discount;

(2) If you are full of shopping in 200 yuan and dissatisfied with 500 yuan, you will get a 10% discount on the marked price;

(3) If the shopping exceeds 500 yuan at one time, 500 yuan will be given the second discount, and the part exceeding 500 yuan will be 20% off.

Someone went shopping twice and paid 168 yuan and 423 yuan respectively. If he bought goods twice at a time, he should pay () yuan.

1、522.8 2、5 10.4 3、560.4 4、472.8

Fill in the blanks. (6 points for each small question, ***36 points)

(1) The school shipped two bundles of saplings, with 240 trees. Prepare to be assigned to the fourth, fifth and sixth grades for planting. For the total number of plants planted in the sixth grade, the ratio of the number of plants in the fourth and fifth grades is 3: 4. We should plant trees in grade four.

(2) An isosceles triangle paper, the ratio of bottom to height is 8: 3. Cut it into a rectangle along the height of the bottom edge. The circumference of a rectangle is 28 cm, but the area of this triangular piece of paper is () square cm.

(3) Rectangular glass container with a length of 20cm, a width of10cm and a height of 20cm, containing some red solution. Xiao Ming wants to know the depth of the solution. He inserted a rectangular wooden strip with a bottom edge of 5 cm and a length of 1 m vertically into the bottom of the container. After taking it out, he measured it, and the red part of the wooden strip was 16 cm long. It turns out that the red solution in the container is () cm deep.

(4) On the right, ABCD is a right-angled trapezoid. Given that OE is perpendicular to DC, AD= 10 cm, and the area of triangular BOC is15cm 2, the area of triangular ADO is () cm 2. Germany is () centimeters long.

(5) In the field with 10 ridges side by side, two ridges are selected to plant crops A and B, and one ridge is planted for each crop. In order to be beneficial to the growth of crops, the row spacing of crops A and B is required to be no less than 6 ridges, so there are () different ridge selection planting methods.

(6) It is known that the sum of two numbers is 1576, and the sum of two new numbers is 4375 after the numerical order of these two numbers is reversed respectively. It turns out that these two numbers are () respectively.

5. Answer the following questions. (6 points for each small question, *** 12 points)

(1) Two trains, A and B, leave from A and bilibili respectively, and the directions are opposite. Car A starts 20 minutes first. When they meet, car B travels 8 kilometers more than car A. It is known that the speed ratio of car A and car B is 3∶4, and it takes 2.5 hours for car B to travel from mile to mile to station A. Find the speed of car A and car B and the distance between station A and bilibili?

(2) Please observe the following example carefully and learn the size comparison method introduced in the example.

Example: Compare the continued product of 20 with the size of 0.00 1.

Because: the product of the two is,

Product of 20 = product of 10 < product of10 =

& lt0.00 1

So: the continuous product of 20 is less than 0.00 1.

Use the method you have learned to compare the sum of 20 connected products. (Briefly describe the comparison process)

answer

1.( 1) 180,162 (2) 35,8 (3) The maximum value is, and the minimum value is (4) 180.

(5)92(6)8∶9(7) 150.72(8)482(9)8.5( 10)50 1

( 1)×(2)√

( 1) 4 (2) 3 (3) 2,4 (4) 3