Please help solve the elementary school application problems, elementary school problem solving appl

If it takes x days for B to do it alone, then B's work efficiency is 1 x, while A and B's daily work efficiency is 1 6, and A's work efficiency is (1 6-1 x), which is derived from the title.

4/（1/6-1/x)+10/x=1

solution, x=18

The time required for the meeting of A and B is 225 (15+10) = 9 hours.

Then the dog ran a total of 20*9=180 kilometers.

Let the capacity of the first container be x liters, then the capacity of the second container will be 2 (105-x) liters, as the title suggests.

2（105-x）+x/3=105

Solution, x = 63 liters.

1) If the cooperation is completed in 6 days, the work efficiency of the two people is 1 6. And if A does it for 4 days and B does it for 10 days and completes the task, it can be seen as A and B cooperating for 4 days and B doing it for another 6 days. This can be obtained from B:

1-4*1 6=1 3, B: 1 3 6=1 18

Then you have to do 1 (1 18) = 18 (days).

2) You can first calculate the meeting time of A and B: 225 (15+10)=9 (hours) and the time of meeting is calculated by the speed of the dog, and calculate how many kilometers the dog has run: 9*20=180 (kilometers). "This question is actually a brain teaser".

3) According to 1 2 that can fill the first container and the second container, or 1 3 that can fill the second container and the first container, we can know that 2 3 of the first container = 1 2 of the second container.

The first container is water divided by 3 parts of one container plus 2 parts of 2 containers and multiplied by 3 parts: 105 (3+2) = 21 (liters) 21*3 = 63 (liters).

The second container is 4 3 of one container: 63 * (4 3) = 84 (liters).

You're in 6th grade, I've asked the teacher, and it's (I'm also in 6th grade).

1.Cooperation efficiency of A and B: 1 6

B efficiency (1-4*1 6) 6=1 18

It takes 18 days for Team B to do it alone.

3.Solution: Let the capacity of the first container be a, and the capacity of the second container be ba+b 2=105

a/3+b=105

Solution. a=63

b=84

1.Set up team B to do it alone for x days. (1 6-1 x)*4+1 x*10=1 solution x=18

km) 3.Let the capacity of the first container be a liter and the capacity of the second container be b liters.

a+1 2*b=105 1 3*a+b=105 gives a=45 b=60

A selection of primary school problem-solving problems.

The more practice for the test questions, the better, so that you can master the solution ideas of various test types and apply them freely in the exam. Please refer to the following I have compiled for you, I hope that the students' practice of the test questions can make the results improve by leaps and bounds'Develop.

Problem solving:

1.The school bought back 3 boxes of table tennis balls, 8 in each box, and distributed them to 4 classes in the second grade on average, how many table tennis balls did each class get?

2.The bear picked up 9 corns, and the little grip closed the monkey to check 4 times that of the bear, how many corns did they pick up in total?

Application:

1. There are 42 people in an air-conditioned car, 8 people get off the bus halfway, and 16 people come up, how many people are in the car now?

2. A total of 54 loaves were made in the bakery, 8 were bought by the children in the first team, and 22 were bought by the children in the second team.

3. A total of 94 cans were collected in each group, of which 34 cans were collected in the first group and 29 cans were collected in the second group. How many cans did the third group collect?

4.The new computer company has 87 computers, 19 in the morning and 26 in the afternoon, how many are left? (Answer in two ways).

5.There were 22 sheets of waxed paper in the class, and 27 were bought. There are 38 tickets used for the party, how many are left?

6.The Children's Palace has purchased 52 new violins and 20 violins less than violins.

7.There are 36 passengers in a bus, 8 people go down to Fuzhou Road, and 12 people come up, how many people are on the bus at this time?

fu0106 said: Hello.

There are n seats in the first row.

The column equation is as follows:

n+（25-1）×2＝70

N 70-48 22 (seats).

There are 22 seats in the first row, 22+70) 25 2 1150 seats.

A: There are 1,150 seats in the theater.

Note: Determine the number of seats in the first row first, the first row + the last row) The number of rows 2 total digits. 22+24+26+28……+70＝（22+70）×25÷2＝1150

Good luck and goodbye.

Let the first row be x, then the last row is x+(25-1)*2=70 x is 22, and the total number of seats is 22*25+2*(1+2+3+4+..)24）=550+2*25*12=550+600=1150

The number of seats in the first row plus the number of seats in the last row is equal to the number of seats in the second row plus the number of seats in the penultimate row, and so on, with the number of seats in the middle row equal to half of the sum of the seats in the first and last rows.

So the 13th row is the middle one, and he has 70-2*12=46

There are a total of 46 + 2 * 46 * 12 = 46 + 1104 = 1150

There are 70-2 seats in the first row * (25-1) = 22.

There are a total of (22 70) * (25-1) 2 (22 70) 2 = 1150.

First, calculate the seats in row 1 and set it as: x-column is titled x+(25-1)*2=70 and find x=22

The total number of seats is (22 + 70) * 25 2 = 1150

1.86 2 3 16 500 (basket).

2.(1) From 22:40 to 7:00 the next day, it is 8 hours and 20 minutes 25 to 3 hours.

130 25 3 1080 (km).

2) 118 18 2124 (pcs).

Give it a portion.

Solution: Set up a pack of x copies of science and technology books.

15×20+12x=660

300+12x=660

12x=360

x=30A: 30 copies per pack of science and technology books.

Set up a pack of x copies of science and technology books.

Then according to the title.

15*20+12x=660

12x=660-300

12x=360

x = 30 science and technology books per pack of 30 copies.

10 liters = 10 cubic decimeters.

10 (dm.)

The water surface is 6-2=4 decimeters from the mouth of the container.

cubic decimeters = 8000 cubic centimeters.

Edge length = 20 cm.

First of all, you need to know that 1 liter of water is 1 cubic decimeter.

1: Calculate how many decimeters the height of the water surface is from the mouth of the container: 6-(10 2 decimeters.

2: Find the edge length of the cube: first calculate the volume of the iron block: (

18-10 = 8 cubic decimeters;

Then calculate the edge length: 8 cubic decimeters open = 2 decimeters.

Check: 2 2 2 = 8.

Answer: The height of the water surface is 4 decimeters from the mouth of the container; The cube of iron is 2 decimeters long.

1l = 1dm cube.

1: Calculate how many decimeters the height of the water surface is from the mouth of the container: 6-(10 2 decimeters.

2: Find the edge length of the cube: first calculate the volume of the iron block: (

18-10 = 8 cubic decimeters;

Then calculate the edge length: 8 cubic decimeters open = 2 decimeters.

Check: 2 2 2 = 8.

Answer: The height of the water surface is 4 decimeters from the mouth of the container; The cube of iron is 2 decimeters long.

It's simple.

Bottom: 25 * 25 = 625 square centimeters.

4 sides: 25 * 35 * 4 = 3500 square centimeters need white iron: 625 + 3500 = 4125 square centimeters = square decimeters.

The cuboid has six sides, and since there is no cover, the area of the five sides under the front, back, left and right is enough.

2425 (square centimeters).

square decimeter) A: At least square decimeter iron sheet is required.

The surface area of the box minus the area of the cap;

25 25 + 25 35 2 + 25 35 2 = 4125 square centimeters = square decimeters.

Let the side length of the new square be x

Then the length and width of the original rectangle are x+4 and x-2 respectively

The area of the square x 2, the area of the rectangle is (x+4) (x-2) column equation x 2=(x+4) (x-2).

x^2=x^2+2x-8

2x=8x=4, so the length and width of the original rectangle are respectively.

4-2 = 2 cm.

4+4=8 cm.

Solution: Let the original length be x width y

x-4=y+2 （1）

x-4)^2=xy （2）

Solution (1) yields x=y+6

Substitute x=y+6 into (2).

Get (y+2) 2=(y+6)y

y^2+4y+4=y^2+6y

6y-4y=4

2y=4y=2x=y+6=8

A: The length is 8 cm and the width is 2 cm.

Let the length be x and the width y

xy=(x-4)(y+2)

x-4=y+2

Solve this system of equations to get x=8, y=2