2. Let A, B, C and D be natural numbers, and define < A, B, C, D >= A.D.+B.C.. then

3. The sum of number A and number B is 66.55, and the decimal point of number B is shifted one place to the right, which is equal to number A, which is ().

The inner angle of triangle is 20 degrees. If you put it under the magnifying glass of 10 times, the degree you see is ().

5. The frozen volume of water will increase by111,so the volume will decrease when it is frozen into water ().

6. A square, if one side is reduced by 40% and the other side is increased by 6 meters, the rectangle obtained is exactly equal to the area of the original square, then the area of the square is ().

7. The greatest common divisor of numbers 543543 and 345345 is ().

8.7 The quotient of ÷ 31is a cyclic decimal, so it is judged that a cyclic node is at most () and there is no division.

9. The diameter of a circle is 40 cm. Cut a sector with a central angle of 72 from the circle, and its circumference is () cm.

10. A fraction of a molecule plus a number equals 5/7; If you subtract the same number from its molecule, this score is equal to 1/2, and this score is ().

1 1. There are 465 students in a school, of which 2/3 girls are 20 less than 4/5 boys, so boys are less than girls ().

12. The circumference of a rectangle is 130 cm. If its width increases by 1/5 and its length decreases by 1/8, a new rectangle with the same circumference will be obtained. It turns out that the area of a rectangle is () square centimeters.

Two. Calculation (4 points for each question, *** 12 points)

Three, the application problem (write the main problem-solving process or reasoning process, each problem 10, ***60 points)

1. For a project, Party A and Party B will cooperate for four days, and Party B will complete it alone for five days. It is known that Party A finishes more than Party B every day 1/30. How many days does it take for Party A and Party B to do this project alone?

The journey is divided into three sections: uphill, flat and downhill. The ratio of the length of each section is 1: 2: 3, and the ratio of time when someone walks these three sections is 4: 5: 6. It is known that he walked 2.5 kilometers per hour and the whole journey was 20 kilometers when going uphill. How long will it take this person to complete the journey?

3. There are 28 more girls than boys taking part in the math contest. After the examination, all the boys got excellent grades, while 1/4 of the girls didn't get excellent grades. It is known that 42 boys and girls have achieved excellent results, accounting for 20% of the whole grade. How many students are there in the whole grade?

4. There are several piles of chess pieces, each pile has the same number of pieces, and each pile has 28% white chess pieces. Xiao Ming took half of a pile of chess pieces, all of which were black spots. Now white pieces account for 32% of all pieces, so how many piles of pieces are there?

5. What is the sum of the two shadow areas as shown in the figure (unit: cm)?

6. Lele needs to walk home from school 14 points, Jingjing needs to walk home from school 14 points. It is known that Jingjing travels more home than Lele 1/6, and Lele walks more 12 meters per minute than Jingjing. How many meters is Jingjing's journey home?

Other issues

On Saturday, some young pioneers went to the gym to clean the lawn. There are two lawns in the stadium, one of which is twice as big as the other. After cleaning the big lawn for half a day, all the young pioneers were divided into two halves, one half continued to clean the big lawn and the other half cleaned the small lawn. After cleaning for half a day, the big lawn was cleaned, but there was still a small lawn left, which a student could clean in one day. Q: How much does it cost for a classmate to clean the lawn a day? How many young pioneers are there? Briefly explain why. Which question?