2. Dig a cylinder with a bottom radius of 1 cm and a height of 1.5 cm in the center of each face of a cube with a side length of 4 cm, and find the graphic surface area.
3. Only three containers with irregular shapes (each with only one capacity), 10L, 7L and 3L, 10L are filled with water. Now it is required that only 5L of water can be poured from the existing container. Is the demand accurate? We assume that there is no overflow and adhesion during dumping.
Interviewee: qap 19950602- trainee guide level 2 12-9 20:49.
1. Xiaohua bought a batch of ballpoint pens and just paid 10 yuan. He bought two kinds of ballpoint pens, 65438+65438 in 0 yuan and 65438+50 in 0 yuan. How many ballpoint pens did he buy?
2. There are two kinds of trucks, truck A has a load capacity of 6 tons and truck B has a load capacity of 8 tons. The existing coal 144 tons needs to be transported at one time. There should be no less than 4 trucks of each type, and each truck should be fully loaded. How many trucks do Party A and Party B need?
3. A math exam, using a five-level scoring system (5 points is the highest, followed by 4 points, …). The average score of boys is 4, that of girls is 3.25, and that of the whole class is 3.6. If there are more than 30 students and less than 50 students in the class, how many boys and girls have taken the exam?
4. 0.45 yuan per ton when the water fee in a certain place does not exceed 10 ton; When the water consumption exceeds 10 ton, each ton of 0.8 yuan and Zhang's family will pay more than Li's. If the water consumption of both families is integer tons, they will pay more to 3.3 yuan. How much does each family pay for water?
5. There are three commodities A, B and C. If you buy three A's and seven B's, 1 C * * *, you need 3 15 yuan. If you buy 4 pieces of Party A, 2 pieces of Party B 10 and 3 pieces of Party C 1 0, you need 420 yuan. How much does it cost to buy A, B and C now?
Respondent: peerless immortal-probation level 112-1019: 58.
1. A fifth ton is ()% of a quarter ton, and a fifth ton is less than a quarter ton ()%.
80% of 2.20 is () 20 is () 80%.
3.A number is 60% more than B number, A number is ()% of B number, and B number is ()% of A number.
The number of boys is 80% of that of girls. What percentage of girls are in the class? What percentage of boys are in this class?
5. Among the four numbers of 0.3, 1/3, 3% and 1 1/3, the largest number is () and the smallest number is ().
6. Number A is 4/5 of number B, number A is less than number B ()%, and number B is greater than number A ()%.
Respondent: 729 186648- probation level 112-1517:18.
76. A bus travels from the departure station to the terminal station (including the departure station and the terminal station) for 8 stops. It is known that there are 0/00 people getting on at the first six stops and 80 people getting off at the terminal. How many passengers got on at the last six stops and got off at the terminal?
77. Given the algebraic expression, the value at that time was 1-, 2,2, which was not equal to 0, so what was the value of the algebraic expression at that time?
78. As shown in the figure, three marbles move counterclockwise at the same time on a circular track. It is known that A catches up with B in 10 second, C catches up with B again in 30 seconds, A catches up with B again in 60 seconds and C catches up with B again in 70 seconds. How long did it take B to catch up with C?
79. Rational numbers are not 0. Try to find the value of algebraic expression 2000.
80. Known as an integer, if so, please prove:.
Answers and tips
76. Suppose 1 passengers from station 7 get off at station 2 and get off at station 8. The passengers are:
Obviously there should be: =
Known = 100, = 80,
Replace with 100+, i.e.
This shows that ***20 passengers got on the bus from the first 6 stops and got off at the terminal.
77. Substitute them into algebraic expressions respectively, and get
Thus, it is possible to obtain the values to be substituted into the first and third equations, and obtain
∴; And then get
Substitute sum into algebraic expression and get =
; Then substitute, that is, the value of algebraic expression at that time is
78. Let the speed of A be the speed of B, and the speed of C be the speed of L. It takes 50 seconds for A to run one lap more than B, so there is-= ①.
It takes 40 seconds for A to run one lap more than C, so there is-= ②.
②-① Available-=-= ③
④
⑤
In the initial position of A, B and C, the distance between B and C = the distance between A and C-the distance between A and B..
=(-)×30-( -)× 10; Time taken for b to catch up with c =
= seconds. So at 1 10 seconds, B caught up with C.
79. None is zero, none is zero. They can't all be the same number, so they must be one positive and two negative or one negative and two positive. therefore
That is, there must be two symbols with the same sign and the other symbol with the opposite sign, that is, its value is two+1, one-1 or two-1 and one+1.
∴
Therefore,
80. Known and known integers exist, so
So according to separability
5 1. Divide a rectangle with a length of and a width of into six identical small rectangles, and then draw a shape similar to the letter m in the rectangle. If the graphic area of the letter m is s, then S = _ _.
52. In rational numbers -3, +8,-,0. 1, 0,-10.5, -0.4, all positive sums are filled in the zero of the following formula, all negative sums are filled in the □ of the formal formula, and the calculation results of the following formula are filled in the horizontal line on the left of the equal sign. 〇÷□=__。
53. Number-filling calculation: fill in the smallest natural number in zero, the smallest non-negative number in δ, the integer not less than -5 and less than 3 in□, and write the calculation result of the following formula on the horizontal line to the right of the equal sign. (〇+□)×△=__。
Respondents: Fuwai No.2 Primary School-Magic Apprentice Level 112-1517: 41.
1. has a trapezoid, the ratio of the length of its upper base to its lower base is 3: 7, and its height is 10 cm. If the upper bottom is increased by 28 cm, the trapezoid becomes a parallelogram. What is the area of this trapezoid () square centimeter?
2. Zhang and Wang made 200 parts at the same time, Zhang made one in 4 minutes and Wang made one in 6 minutes. When they finished the task, each of them earned ()?
3. Two cars, A and B, travel from the East Village to the West Village at the same speed, and B does not start until the first car leaves 12km. After arriving at the West Village, Bus A immediately went back the same way, driving 1 of the distance between the two villages, and just met Bus B, asking how far () kilometers away the two villages are.
4. Grade three students 182, including 1 person, class two workers 84, class two and class four students 9 1 person, class four students 1 person and class three students 87 ()?
5. A rope, the first time cut off the total length of 1, the second time cut off 6 meters, at this time there is still half, this rope was originally () meters long?
6. The age of the son is the father's 1. The sum of the ages of father and son was 49 three years ago. How old are the father and son now?
7. The proportion of cement, sand and stone used in preparing concrete is 2: 3: 5, and now there are 2.5 tons of stones, and cement () tons are used. Sand () tons?
Respondent: 630 164998- assistant level 212-1613: 08.
1. The students went camping. A classmate went to get a bowl, and the teacher asked him a few. He said 55. Did the teacher ask how many people want bowls? He replied, 1 One rice bowl for one person, one vegetable bowl for two people and one soup bowl for three people? Please count how many students lead the bowl.
Answer: 30
If 1 person has a rice bowl, two people have a vegetable bowl and three people have a soup bowl, then after the same score, six people use 1 1 bowl and five 1 1 people, that is, 55 people.
2. 100 students took the exam, 8 1 students answered the first question correctly, 9 1 students answered the second question correctly, 85 students answered the third question correctly, 79 students answered the fourth question correctly, 74 students answered the fifth question correctly, and those who answered more than three questions correctly were considered qualified. Q: How many people are qualified?
The answer is uncertain.
Correct answer: 8 1 9 1 85 79 74.
Wrong answer: 19 9 15 2 1 26.
{8 1+9 1+85+79+74} divided by 3 = answer.
3. In still water, the speed of ship A is 19 kilometers per hour, the speed of ship B is 23 kilometers per hour, and the current speed is 4 kilometers per hour. Two hours after Ship A sailed out of the port, Ship B sailed in the same direction. How many hours can ship B catch up with ship A?
Answer: A's 2-hour journey is: 2*( 19+4)=46 kilometers.
The catching-up time of B is 46/(23-19) =11. 5 hours
4. Party A, Party B and Party C jointly repair the fence. Party A and Party B will complete it in five days 1, and the remaining 1 two days. Then Party A and Party C jointly maintained it for five days. 600 yuan asked Party B how much to share.
Party A and Party B * * * did 1/3, and the sum of Party A and Party B's work efficiency is 1/3 divided by 5, and it is115;
b * * * did( 1- 1/3)* 1/4 = 1/6； The ergonomic sum of ethylene and propylene is 1/6 divided by 2 to get112;
a * * * did( 1- 1/3- 1/6)= 1/2； The sum of the working efficiency of A-C is 1/2 divided by 5, and110 is obtained;
The sum of the above three groups of work efficiency is 2 (A+B+C), that is, (115+112+110) =/. Divided by 2, we get the ergonomic sum of A, B and C, that is, 1/4 divided by 2, we get 1/8.
Because the work efficiency of Party A and Party C is110, the work efficiency of Party B is calculated by subtracting the work efficiency of Party A and Party C, that is, (1/8-1) =1/40.
Because Otsuichi worked for (5+2) days, multiplied by the work efficiency 1/40, it is 7/40, which means that Party B has completed 7/40 of all the projects. If the total amount of this job is 600 yuan, Party B should get 7/40,600 * 7/40 =105 of 600.
There are 49 students in a class of * * * for three years, including 3 more boys than girls. How many boys and girls are there?
There are 230 books on the shelves in the library. If you take out 15 books from the lower shelf and put them in the upper shelf, the number of books in the two shelves is the same. How many books are there on the shelves?
7. There are 500 monkeys in three monkey mountains, the number of monkeys in the second mountain is 3/5 of that in the first mountain, and the number of monkeys in the third mountain is 39 less. How many monkeys are there on the third mountain?
8. The number of students in lower grades in a primary school is 2/3 of that in middle and high grades, 3/5 of that in middle and high grades, and the number of students in high grades is 72 less than that in middle schools. How many people are there in this school?
9. A children's story book in the bookstore sold 30% on the first day and 120% on the second day, 30 more than on the first day. How many books are there in this story book bookstore?
Sold on the first day: 30 divided by {120%- 100%}
I * * * sell: 30% on the first day.
10. In the school sports meeting, girls account for one-sixth of the class, boys account for one-quarter of the class, and boys are four more than girls. How many people are there in this class?
1 1. The minute hand of the wall clock {equal to the radius of the clock} is 20 cm long. After 45 minutes, how far did the tip of this minute hand move?
12. Six-grade students in Guangxin Primary School 128 students, 5 out of 8 students reached the physical education standard, while 2 out of 5 girls and 3 out of 5 boys accounted for a few percent of the total number of sixth-grade students.
Respondent: 4296233 19- assistant level 212-1619: 37.
This is still limited, you can look at this website/competition/index.html.
Very complete.
Respondent: liuchunyan 1984- probation level 112-191:31.
1. Reading a book, you read 1 on the first day, 1 on the second day, and read 8 pages on the third day, which is just half of reading a complete book. How many pages are there in this book?
There are many students in the school. There are 72 more boys than 1 of the total school population, and 20 fewer girls than 3/5 of the total school population. How many students are there in the school?
3. From A to B, a car traveled 42 kilometers in the first hour and 65438+5/0 in the second hour, and the remaining distance was twice as short as the distance it had traveled and 6 kilometers less. What is the distance between a and b?
4. One scientific research group takes part in part-time study, accounting for 5/2 of the whole group, and the other 3 people take mechanical courses, that is, 15 people take part in university study. How many people are there in this group?
Respondent: jjoozzz- Tong Sheng Grade 112-1921:03.