1. A, B, and C built a wall together. A and B worked together for 5 days to complete 1/3, B and C worked together for 2 days to complete the remaining 1/4, and then A and C worked together to build a fence. It took 5 days to complete the repair. The labor compensation for the entire project was 600 yuan. How much should B get?
A and B *** did 1/3. The sum of the work efficiency of A and B is 1/3 divided by 5, which is 1 /15;
B and C*** did (1-1/3)*1/4=1/6; the sum of the work efficiency of B and C is 1/6 divided by 2, which is 1/12 ;
A and C *** did (1-1/3-1/6) = 1/2; the sum of the work efficiency of A and C is 1/2 divided by 5, which is 1/10; < /p>
Add the above three sets of work efficiency sums to get the work efficiency sum of 2 (A + B + C), that is (1/15 + 1/12 + 1/10) = 1/4; then divide Dividing 2, we get the sum of the work efficiency of A, B, and C, that is, 1/4 divided by 2, we get 1/8.
Because the sum of the work efficiency of A and C is 1/10, the sum of the work efficiency of A, B and C minus the sum of the work efficiency of A and C is the work efficiency of B, that is (1/8-1/ 10)=1/40.
Because B worked on *** for (5+2) days, multiplied by the work efficiency 1/40, we get 7/40, which means that B completed 7/40 of the entire project, and the total amount of the job If it is 600 yuan, B should get 7/40 of 600, using 600*7/40 = 105 yuan.
2. There are 49 students in Class Three ***, among whom there are 3 more boys than girls. How many boys and girls are there?
3. There are 230 books on the bookshelves in the library and on the lower floor. If you take 15 books from the lower floor and put them on the upper floor, there will be the same number of books on the two shelves. How many books are there?
1. The students went to participate in camping activities. A classmate went to receive bowls. The teacher asked him how many people wanted bowls. He said 55. Did the teacher ask how many people wanted bowls? He replied: One rice bowl for one person, one vegetable bowl for two people, and one soup bowl for three people? Please count how many students receive bowls?
Answer: 30
If one person has a rice bowl, 2 people have a vegetable bowl, and 3 people have a soup bowl, then after the equal division, 6 people will use 11 bowls, and 5 An 11 is 55 people, which is 30 people.
2.100 students took the exam. 81 students answered the first question correctly, 91 students answered the second question correctly, 85 students answered the third question correctly, and 79 students answered the fourth question correctly. There are 74 students who answered the fifth question correctly. Those who answered three or more questions correctly are considered qualified. Question: How many students are qualified?
Not sure about the answer
Correct answer: 81 91 85 79 74
Incorrect answer: 19 9 15 21 26
{81+91 +85+79+74} divided by 3 = answer
3. In still water, the speed of ship A is 19 kilometers per hour, and the speed of ship B is 23 kilometers per hour: the speed of the water flow is 4 kilometers per hour. After ship A leaves the port and sails downstream for 2 hours, ship B leaves in the same direction. How many hours will it take for ship B to catch up with ship A?
Answer: A sails out for 2 hours The distance traveled is: 2*(19+4)=46 kilometers
The time for B to catch up is: 46/(23-19)=11.
5 hours
Answer: 429623319 - Probation period level one 11-30 18:31
1. A, B, and C built a wall together. A and B worked together for 5 days to complete the 3 points 1, B and C worked together to complete the remaining 1/4 in 2 days, and then A and C worked together to complete the work in 5 days. The labor remuneration for the entire project was 600 yuan, how much should B share.
A and B*** did 1/3. The sum of A and B's work efficiency is 1/3 divided by 5, which is 1/15;
B and C*** did (1-1/3)*1 /4=1/6; the sum of the work efficiency of B and C is 1/6 divided by 2, which is 1/12;
A and C *** did (1-1/3-1/6) =1/2; the sum of the work efficiency of A and C is 1/2 divided by 5, which is 1/10;
Add the above three sets of work efficiency sums, and you will get the sum of 2 (A + B + C) The sum of the work efficiency is (1/15+1/12+1/10) = 1/4; and then divided by 2, we get the sum of the work efficiency of A, B, and C, that is, 1/4 divided by 2, we get 1/8.
Because the sum of the work efficiency of A and C is 1/10, the sum of the work efficiency of A, B and C minus the sum of the work efficiency of A and C is the work efficiency of B, that is (1/8-1/ 10)=1/40.
Because B worked on *** for (5+2) days, multiplied by the work efficiency 1/40, we get 7/40, which means that B completed 7/40 of the entire project, and the total amount of the job If it is 600 yuan, B should get 7/40 of 600, using 600*7/40 = 105 yuan.
2. There are 49 students in Class Three ***, among whom there are 3 more boys than girls. How many boys and girls are there?
3. There are 230 books on the bookshelves in the library and on the lower floor. If you take 15 books from the lower floor and put them on the upper floor, there will be the same number of books on the two shelves. How many books are there?
There are 500 monkeys in the three monkey mountains. The number of monkeys on the second mountain is only 3/5 of the number of monkeys on the first monkey mountain. The number of monkeys on the third monkey mountain is smaller than that on the second mountain. There are 39 monkeys missing on the mountain. How many monkeys are there in the third mountain?
The number of students in the lower grade of a certain primary school is 2/3 of the middle and upper grades, the middle grade is 3/5 of the lower and upper grades, and the upper grade has 72 fewer students than the middle grade. How many people are there in this school?
1. Three kinds of drinks are provided at one meal. Statistics after the meal showed that a total of 78 bottles of the three drinks were consumed; on average, every 2 people drank one bottle of drink A, every 3 people drank one bottle of drink B, and every 4 people drank one bottle of drink C. Ask, how many people are attending the dinner?
Primary school math problems should not be solved using equations
The average number of drinks consumed per person is: 1/2+1/3+1/4=13/12 bottles
The number of people attending the dinner is: 78*12/13=72 people
The sum of 2, 1+2*3+4*5+6*7+……+100*101 Is it an odd number or an even number?
Odd number
Because 1+even number+even number+......+even number=odd number
3. A math test***20 It is a question that requires 2 points for a correct answer, no points for an unanswered question, and a deduction of 1 point for a wrong answer. Xiao Ming scored 23 points, and the questions he did not answer were even numbers.
Ask, how many questions did he get wrong?
3)
This question should be classified as a chicken and rabbit in the same cage problem.
1. The full score is 40 points
2. Xiao Ming only scored 23 points, 40-23 = 17 points less
3. One point will be deducted for each wrong question, which means you will get 3 points less than if you got it right.
0 points will be deducted for each wrong question, which means you will get 2 points less than if you got it right.
4. Since 17<3*6, Xiao Ming can get up to 5 wrong questions
5. The following is divided into several possible situations for further discussion.
Assuming that Xiao Ming did not get one question wrong, then the 17 points are all caused by not doing it, but 17 is not a multiple of 2, so this situation cannot happen.
Suppose Xiao Ming got 1 question wrong, 17-3=14, then he did not do 14/2=7 questions. The answer is to get 12 questions right, 1 question wrong, 7 questions not done, and *** gets 23 points
Suppose Xiao Ming got 2 questions wrong, 17-6=11, but 11 is not a multiple of 2, so This situation cannot happen.
Suppose Xiao Ming got 3 questions wrong, 17-9=8, then he didn’t do 8/2=4 questions. The answer is 13 questions were answered correctly, 3 questions were wrong, and 4 questions were not answered, and *** scored 23 points
Assume that Xiao Ming got 4 questions wrong, 17-12 = 5, but 5 is not a multiple of 2, so This situation cannot happen.
Suppose Xiao Ming got 5 questions wrong, 17-15 = 2, then 1 question was not done. The answer is 14 questions were answered correctly, 5 questions were wrong, and 1 question was not answered, and *** scored 23 points
So there should be three answers
. The original price of a certain product is 50 yuan. Due to poor sales, prices were reduced by 10% in October. The price began to increase in November, and the price in December was 64.8 yuan. What is the average price increase rate in the two months of November and December?
2. The fruit company purchased 52,000 kilograms of apples at a purchase price of 0.98 yuan per kilogram, and paid a total of 1,840 yuan in freight and labor fees. It is estimated that the loss during the journey is 1%. If we hope to make a profit of 17% after all purchases are made and sold, then how much yuan should the retail price of apples per kilogram be set?
3. The purchase price of a certain commodity is reduced by 15%, but the selling price remains unchanged, resulting in a 21% increase in profit margin. Find the current profit margin.
Answer; 1. The original selling price of a certain product is 50 yuan. Due to poor sales, prices were reduced by 10% in October. The price began to increase in November, and the price in December was 64.8 yuan. What is the average price increase rate in the two months of November and December?
The price in October is: 50*(1-10%)=45 yuan
64.8/45=1.44
Because: 1. 2*1.2=1.44, so the average growth rate is: 1.2-1=0.2=20%
2. The fruit company purchased 52,000 kilograms of apples, and the purchase price per kilogram It is 0.98 yuan, and the total payment for freight, labor fees, etc. is 1840 yuan. It is estimated that the loss during the journey is 1%. If we hope to make a profit of 17% after all purchases are made and sold, then how much yuan should the retail price of apples per kilogram be set?
Solution 1
Suppose: the price of apples per kilogram is x yuan, then the meaning of the question is:
(52000*0.98+1840)*(1+17 %)=52000(1-1%)x
It can be solved:
x=1.2 yuan.
So the price should be 1.2 yuan per kilogram< /p>
Solution (2)
0.98*52001840=52800 yuan
52800*(1+17%)=61776 yuan
61776÷[5.2*10000*(1-1%)]=1.2 yuan
The selling price of apples per kilogram should be set at 1.2 yuan
3. Due to the purchase price of a certain commodity Decrease by 15%, the selling price remains unchanged, which increases the profit margin by 21%. Find the current profit margin.
Suppose the original purchase price is 100, then the profit is are the same, then
The current profit is 10X-85=15+X
The profit rate is (15+X)/85=X/1021%
3/17+X/85=X/100. 21X=19
Then the current profit rate is: (15+19)/85=40%
< p>1. The students went to participate in camping activities. A classmate went to receive bowls. The teacher asked him how many people wanted bowls. He said 55. Did the teacher ask how many people wanted bowls? He replied: One rice bowl for one person, one vegetable bowl for two people, and one soup bowl for three people? Please count how many students receive bowls?Answer: 30
If one person has a rice bowl, 2 people have a vegetable bowl, and 3 people have a soup bowl, then after the equal division, 6 people will use 11 bowls, and 5 An 11 is 55 people, which is 30 people.
2.100 students took the exam. 81 students answered the first question correctly, 91 students answered the second question correctly, 85 students answered the third question correctly, and 79 students answered the fourth question correctly. There are 74 students who answered the fifth question correctly. Those who answered three or more questions correctly are considered qualified. Question: How many students are qualified?
Not sure about the answer
Correct answer: 81 91 85 79 74
Incorrect answer: 19 9 15 21 26
{81+91 +85+79+74} divided by 3 = answer
3. In still water, the speed of boat A is 19 kilometers per hour, and the speed of boat B is 23 kilometers per hour: the speed of the water flow is 4 kilometers per hour. After ship A leaves the port and sails downstream for 2 hours, ship B leaves in the same direction. How many hours will it take for ship B to catch up with ship A?
Answer: A sails out for 2 hours The itinerary is: 2*(19+4)=46 kilometers
The time for B to catch up is: 46/(23-19)=11.5 hours
Answer: 429623319 - Probation period level 11-30 18:31
1. A, B, and C built a wall together. A and B worked together for 5 days to complete 1/3, and B and C worked together for 2 days to complete the rest. 1/4 of it, and then A and C worked together for 5 days to complete it. The labor remuneration for the entire project was 600 yuan. How much should B share?
A and B *** completed 1/3 of A and B's work. The sum of work efficiency is 1/3 divided by 5, which is 1/15;
B and C*** did (1-1/3)*1/4=1/6; the sum of work efficiency of B and C It is 1/6 divided by 2, and we get 1/12;
A and C *** did (1-1/3-1/6) = 1/2; the sum of the work efficiency of A and C is 1 /2 divided by 5, we get 1/10;
Add the above three sets of work efficiency sums to get the work efficiency sum of 2 (A + B + C), that is (1/15 + 1/12 +1/10) = 1/4; then divided by 2, we get the sum of the work efficiency of A, B, and C, that is, 1/4 divided by 2, we get 1/8.
Because the sum of the work efficiency of A and C is 1/10, the sum of the work efficiency of A, B and C minus the sum of the work efficiency of A and C is the work efficiency of B, that is (1/8-1/ 10)=1/40.
Because B worked on *** for (5+2) days, multiplied by the work efficiency 1/40, we get 7/40, which means that B completed 7/40 of the entire project, and the total amount of the job If it is 600 yuan, B should get 7/40 of 600, using 600*7/40 = 105 yuan.
2. There are 49 students in Class Three ***, among whom there are 3 more boys than girls. How many boys and girls are there?
3. There are 230 books on the bookshelves in the library and on the lower floor. If you take 15 books from the lower floor and put them on the upper floor, there will be the same number of books on the two shelves. How many books are there?
1. The students went to participate in camping activities. A classmate went to receive bowls. The teacher asked him how many people wanted bowls. He said 55. Did the teacher ask how many people wanted bowls? He replied: One rice bowl for one person, one vegetable bowl for two people, and one soup bowl for three people? Please count how many students receive bowls?
Answer: 30
If one person has a rice bowl, 2 people have a vegetable bowl, and 3 people have a soup bowl, then after the equal division, 6 people will use 11 bowls, and 5 An 11 is 55 people, which is 30 people.
2.100 students took the exam. 81 students answered the first question correctly, 91 students answered the second question correctly, 85 students answered the third question correctly, and 79 students answered the fourth question correctly. There are 74 students who answered the fifth question correctly. Those who answered three or more questions correctly are considered qualified. Question: How many students are qualified?
Not sure about the answer
Correct answer: 81 91 85 79 74
Incorrect answer: 19 9 15 21 26
{81+91 +85+79+74} divided by 3 = answer
3. In still water, the speed of boat A is 19 kilometers per hour, and the speed of boat B is 23 kilometers per hour: the speed of the water flow is 4 kilometers per hour. After ship A leaves the port and sails downstream for 2 hours, ship B leaves in the same direction. How many hours will it take for ship B to catch up with ship A?
Answer: A sails out for 2 hours The journey is: 2*(19+4)=46 kilometers
The time for B to catch up is: 46/(23-19)=11.5 hours
4. A and B Three people, C, worked together to build a wall. A and B worked together for 5 days to complete 1/3, B and C worked together for 2 days to complete the remaining 1/4, and then A and C worked together for 5 days to complete. The labor compensation for the entire project is 600 Yuan, ask B how much money should be divided.
A and B *** did 1/3. The sum of the work efficiency of A and B is 1/3 divided by 5, which is 1/15;
B and C *** did (1-1/3)*1/4=1/6; the sum of the work efficiency of B and C is 1/6 divided by 2, which is 1/12;
A and C *** did (1-1/3-1/6) = 1/2; the sum of the work efficiency of A and C is 1/2 divided by 5, which is 1/10;
Combine the above three groups Add the sum of the work efficiency to get the sum of the work efficiency of 2 (A + B + C), that is (1/15 + 1/12 + 1/10) = 1/4; then divide by 2, you get the sum of the work efficiency of A, B, and C , that is, 1/4 divided by 2, we get 1/8.
Because the sum of the work efficiency of A and C is 1/10, the sum of the work efficiency of A, B and C minus the sum of the work efficiency of A and C is the work efficiency of B, that is (1/8-1/ 10)=1/40.
Because B worked on *** for (5+2) days, multiplied by the work efficiency 1/40, we get 7/40, which means that B completed 7/40 of the entire project, and the total amount of the job If it is 600 yuan, B should get 7/40 of 600, using 600*7/40 = 105 yuan.
5. There are 49 students in Class Three ***, among whom there are 3 more boys than girls. How many boys and girls are there?
6. There are 230 books on the upper and lower shelves of the library. If you take 15 books from the lower shelf and put them on the upper shelf, there will be the same number of books on the two shelves. How many books are there?
7. There are 500 monkeys in the three monkey mountains. The number of monkeys on the second mountain is only 3/5 of the number of monkeys on the first monkey mountain. The number of monkeys on the third monkey mountain is smaller than that of the first monkey mountain. There are 39 monkeys missing on the two mountains. How many monkeys are there in the third mountain?
8. The number of students in the lower grade of a certain primary school is 2/3 of the middle and upper grades, the middle grade is 3/5 of the lower and upper grades, and the upper grade has 72 fewer students than the middle grade.
How many people are there in this school?
9. The bookstore brought children’s storybooks from No. 1 Middle School and sold 30% of the books on the first day. The sales on the second day were equivalent to 120% of the first day, which was 30 more books than the first day. How many storybooks of this kind are shipped from the bookstore?
Sold on the first day: 30% divided by {120%-100%}
Sold on the first day: divided by 30% on the first day
10. At the school sports meeting, the girls in a certain class accounted for 1/6 of the class, and the boys took up 1/4 of the class. The number of boys participating was 4 more than the girls. How many people are there in this class?
11. The minute hand of a wall clock {equal to the radius of the clock} is 20 cm long. After 45 minutes, how many centimeters has the tip of the minute hand traveled?
12. There are 128 students in the sixth grade of Xinguang Primary School, and 5/8 of them have reached the physical education standard. The girls who meet the standard account for 2/5, and the boys who meet the standard account for 3/5. There are 30 more boys than girls. What fraction of the total number of boys in the sixth grade is accounted for?