Elementary school math application problems that are difficult for college students

The walking speed of Xiaoming is V1, the speed of Dad's cycling is V2, and the distance from home to school is S. Since the time for Dad to finish 7s 10 is the same as the time for Xiao Ming to finish 2s 10, you can get v2 = times v1. It took the same amount of time for Xiao Ming to walk 7s 10 as usual, so the 5 minutes ahead was derived like this:

In (3s 10 divided by v1) minus (3s 10 divided by v2) is equal to 5 minutes (the speed of cycling is greater than the speed of walking), the time of Xiao Ming's walking is t=s v1=70 3 minutes. Complete!

I'm sorry, the morning is tight, and the answer is miscalculated. Forgive me, haha.

70 for 3 minutes.

But it's a way. I don't know if it's suitable for elementary school students. But it's not complicated, it's just a few reference unknowns.

Is it difficult, I don't know if this kind of question can stump college students?

Analysis: The schematic diagram is as follows:

The ratio of time spent should be 2:7, and the question says that Xiao Ming takes the car 5 minutes earlier than walking, which means that the time from point D to point B is smaller.

Solution: The same distance from point D to point B, the ratio of the time it takes for Xiao Ming to walk to Xiao Ming's car is 7:2, please see the last question.

A rectangular piece of paper, long and wide, should be cut into squares of equal size, so that their area should be as large as possible, and there should be no left after cutting, how many sheets can be cut in total?

There are a total of 36 trees in a row, originally planted every 2m, but now that the trees have grown, they should be planted every 5 meters, how many trees do not have to be changed?

If a farm has 1,500 chickens and ducks, 1 40% of the number of chickens must be 15 less than 40% of the number of ducks. (Equation solution, one equation should not have two different unknowns).

The fifth and sixth grade students of Guanghua Primary School walked to the forest park for a spring outing, and they set off from the school at the same speed. When the ratio of distance traveled to untraveled in grade 5 was 7:2, grade 6 had already covered 5,000 kilometers.

When the sixth grade arrived, the fifth grade still had a fifteenth of the way to go. How many kilometers is the distance from Guanghua Primary School to Forest Park?

A project can be completed by a number of machines within the specified time, and if 2 machines are added, only 7/8 of the specified time is needed to complete; If you reduce the number of machines by 2, you will have to delay it by 2/3 of an hour. Q: How many hours does it take to complete this project with one machine?

The cost of A and B commodities totaled 2,200 yuan, A commodity was priced at 20% of the profit, and commodity B was priced at 15% of the profit, and later at the request of the customer, the two commodities were discounted by 9% according to the price, and the result was still a profit of 131 yuan. Q: How much is the cost of each of the two types of goods?

Let the cost of A be x yuan and the cost of B be (2200-x) yuan, and the column equation:

1+20%)x+(1+15%)(2200-x)]*90%-2200=131[(

x=1200

2200-x=1000

A costs 1200

B costs 1000

2.A primary school held a knowledge competition, each person must answer 20 questions, 5 points for a correct answer, and 3 points for a wrong answer. Xiao Ming scored 76 points after answering 20 questions, how many did he answer incorrectly?

20*5-76=24 points.

24 (5+3)=3 lanes.

Answer: 3 wrong 24

55x150=8250 (min).

77x150=11550 (min).

11550-8250=3300 (min).

Fail: 3300 (77-47)=110 (person) Pass: 150-110=40 (person).

A: ......110 failed and 40 passed.

I'm in 6th grade, and I've learned a little bit about chickens and rabbits in the same cage, and I hope to help you.

I don't know if elementary school students have ever learned binary equations. So two approaches are given:

The binary equation is as follows: Let the number of qualified students be x and the number of failing students be y. The system of column equations x+y=150,55(x+y)=77x+47y, solves: y=110, x=40

The unary equation is as follows: let the number of qualified students be x, so the number of unqualified students is (150-x), and the column equation is: 77x+47(150-x)=150*55, and the solution is:

x=40。So 150-x=150-40=110.

So the number of students who failed was 110.

Fail x people Qualified 150-x people.

77*(150-x)+47*x=150*5511550-77x+47x=8250

30x=11550-8250=3300

x=3300/30=110

110 people failed.

It seems that LZ can go to college not by math to earn points = =..

It's better to use equations!

Solution: There are x number of students who fail and (150 x) number of qualified students.

47x＋77(150-x)]/150=55x =110

A: There are 110 people who failed.

The watchtower lord adopted.

If you didn't learn equations, you can't blame me. Thank you.

Number of qualified students: Number of failing students (55-47):(77-55) 4:11The score of the number of qualified students in the total number is: 4 (11+4) 4 15The number of qualified students is: 4-15*150 40 (people).

The number of people who fail is: 150-40 110 (people).

It can also be done with equations.

Total score: 150*55=8250 (points).

Solution: Qualified student A, failed student (150-a) 77a+47*(150-a)=8250

77a+7050-47a=8250

30a=1200

a=40 number of failers: 150-a=110 (people).

A: The number of students who failed was 110.

Set the number of failers to x

150*55=77*(150-x)+47*xThe solution is x=110

I hope your little sister has learned equations and can understand.

Elementary school students don't know how to do equations, they have to work backwards...A total of 150 * 55 = 8250, if they are all qualified, 150 * 77 = 11550 points, subtracted, is the total score of the average score of the unqualified people, so 3300 (77-47) = 110

Solution: Set the qualified students as Y and the failing students as X.

77x+47y=150x55

x+y=150

Solve the system of equations, x=40

A: The number of students who failed was 40.

I'm a freshman in high school, and this question is really just a question about the system of equations. Little brother, I'm ugly, hehe.

The total score is 150 times 55

If the number of students who fail is x, the number of students who pass is 150-x77 (150-x) + 47x = 55 * 150

solution, x=110

The number of students who failed was 110.

Quite simply, no matter how averaged, the total score is a certain amount.

The number of unqualified people is w:

150x55=77x(150-w)+47w,w=110

If there are unqualified students x, then there are (150-x) qualified students, and (150-x)*77+47x=150*55solution, x=110

If the number of failers is x, then the number of passers is (150-x)150*55=47*x+77*(150-x)x=110

If I'm not mistaken, it should be like this.

Oh, it seems that the landlord is thinking too complicated, I used to be a tutor when I had this, always complicate simple problems, the result is that it can't be done, set the failing Y 47 * x + 77 * y = 150 * 55, and then x + y = 150, hehe.

If the number of failing students is x, then.

150*55-[47*x+77*(150-x)]=0x=110

That is, the number of people who failed was 110.

If the number of students who fail is x, the number of students who pass is 150-x77 (150-x) + 47x = 55 * 150

solution, x=110

The number of students who failed was 110.

Solution: Set the number of qualified students as x. then there is 77x+(150-x)*47=55*150

77x+150*47-47x=55*15030x+150*47=55*150

30x=8*150

x=40 so 40 qualified students and 150-40=110 unqualified students.

55*150=8250 total score.

Let the passer x77*x+47*(150-x)=8250x=40

110 people failed.

What kind of university are you -- it's not going to be the answer, so I won't say more.

Solution: There are x people who fail.

150×55=77×(150-x)+47xx=110

110 failed.

The number of failing students is x

47x+77*(150-x)]/150=55(77*150-30x)/150=55

77-x/5=55

x = 110 The number of students who fail is 110

55 km) The speed of the bus.

55 km) The combined speed of the two vehicles.

198 hours) meeting time.

Combined: 198 (55 hours).

Knowledge points: distance speed = time.

Total distance combined speed = time of encounter.

This is the encounter problem in the itinerary problem, generally used: time and the speed of the two cars = distance The answer to this question is: time = distance speed and.

198 (55+ hours).

If you encounter this kind of problem in the future, just fill in the numbers into the formula.

Also: the pursuit problem is: time speed difference = distance.

I guess I didn't learn about the problem of running water in elementary school.

55 km) The speed of the bus.

55 km) The combined speed of the two vehicles.

198 hours) meeting time.

Knowledge points: distance speed = time.

Total distance combined speed = time of encounter.

Solution: 55*kmh (truck speed).

km 198 hours.

A: ......Hours meet.

The encounter problem was used to figure out the relationship between speed, time, and distance.

Speed s time t

Distance vv t=s v s=t st=v

It's a matter of encounter. Knowledge points: distance = speed * time, distance = time * (speed A + speed B) in the re-encounter problem

Time t = distance (truck speed + bus speed) = 198 (55 + 55 * hours).

Solution: Let's meet after x hours.

Column Equation: (55+.)

x = hours.

When they meet, the total distance traveled by the two cars is 198 km, and the total speed of the two cars is the sum of the speeds of each car, that is, (1 + km hour, so the time elapsed when they meet = distance speed = 198 (1+ hours.

Knowledge points: distance speed = time.

Total distance combined speed = time of encounter.

Set to meet in x hours, from the meaning of the title.

55x+ solution x=

The two cars met after an hour.

It seems that the method of junior high school = =!

If that doesn't work, just do it with 1L.

198 (55+ hours).

Knowledge points: distance speed = time.

Total distance combined speed = time of encounter.

A: The two cars met after an hour.

It's hard for you to be big, aren't you mentally retarded?

It's called very hard, isn't it, I remember what I did in 5 years was harder than that

198 (Note: Walk in the opposite direction, not in the opposite direction!) The catch-up time is equal to the distance divided by the difference in velocity.

198 (55+ hours Knowledge Time * Speed = Distance.)

When the two cars meet, it takes the same amount of time. The two cars go together to complete a full journey. Hour.

In addition to the highest score, the total score of the four subjects: points).

In addition to the lowest score, the total score of the four subjects: points).

The difference between the highest score and the lowest score: 370 347 = 23 (points) or: the total score of the middle 3 subjects: points).

Minimum score: 347).

Maximum score: 370 points).

The difference between the highest and lowest scores is points).

Have you ever studied weighted averages? It is calculated using this principle.

The total score for those three courses is points.

The lowest score is +, and the lowest score is.

The highest score is +, and the highest score is.

Highest Score - Lowest Score =

Answer: The difference between the highest score and the lowest score in Xiao Wang's five subjects is 23 points.

The highest one is set to A, and the lowest one is set to B

According to the meaning of the topic (a+ b+ = (a+

a-b = You don't need to do any math, you can make an appointment. The answer is so much, as for the knowledge points, then I don't know.

Removing the average score of the highest score, then the total score of the middle three subjects + the lowest one.

Remove the average score of the lowest score, then the total score of the middle three + the highest score.

So 370-347=23