90#2=45 boxes
90#5= 18 boxes
A: If every two are packed in a box, they can be packed accurately. If every five are packed in a box, it can also be packed accurately. Because 90 is divisible by 5.
There are 57 balls in the sporting goods store, and every three balls are packed in a box. Can they be properly packed?
57#3+ 19 cases
A: I can just finish it.
3: A and B type a document of 10000 words, A type 1 15 words per minute, and B type 135 words per minute. How many minutes will it take?
10000 # (115+135) = 40 points.
A: It will be completed in 40 minutes.
4. Grade five students plant trees, 13 or 14. Each group has just finished. How many students took part in planting trees in grade five?
13X 14= 192 people
Answer: At least 192 people participated in tree planting in the fifth grade.
Although the following questions belong to practical problems, they are related to equations. I solved it with equations.
5: Two cars go back and forth from one place. One car has a speed of 365,438+0 kilometers per hour, and the other car has a speed of 44 kilometers per hour. How many minutes later, the two cars are 300 kilometers apart?
Equation:
Solution: Two cars meet after X point.
3 1X+44X=300
75X=300
X=4
4 hours =240 minutes
Answer: After 240 minutes, the distance between the two cars is 300 kilometers.
6: Two engineering teams will excavate a tunnel with a length of119m, and two teams will carry out construction from both ends. Team A digs 4 meters every day, while Team B digs 3 meters every day. How many days does it take to dig the tunnel?
Solution: Set X days to dig tunnels.
3X+4X= 1 19
7X= 1 19
X= 17
Answer: 17 days, the tunnel was dug.
7. School chorus and dance team 140 people. There are six times as many people in the chorus as in the dance team. How many people are there in the dance team?
Solution: There are X people in the dance team.
6X+X= 140
7X= 140
X=20 people
A: There are 20 people in the dance team.
From here on, this is not an equation problem.
8. The two brothers walked from home to the gym at the same time, with a length of 1300m. My brother walks 80 meters per minute, and my brother rides his bike to the gym at a speed of180 meters per minute, and will be right back. On the way, he met his brother. How many minutes did my brother walk?
1300x2 = 2600m 2600#( 180+80)
=2600#260
= 10 point
Answer: At this time, my brother left 10 minutes.
At 9 o'clock on Children's Day, Mr. Wang bought 360 biscuits, 480 sweets and 400 fruits, made a beautiful gift package and distributed it to the children as gifts. How many gift packages can he make at most?
360+480+400= 1240
Answer: You can make at most 1240 small gift packages.
10: Naughty bought 40 balloons and invited his classmates to blow them at home. In order to share the balloons equally, how many students should be invited to blow them? Naughty not to participate.
40#2=20 people 40#4= 10 people 40#5=8 people.
40#8=5 people 40#@0=4 people 40#20=2 people.
A: There are six ways to invite students, namely: 20, 10, 5, 8, 4 and 2.
1 1: trapezoidal corn field with upper bottom 15m, lower bottom 24m and height 18m. There are 9 corn plants per square meter on average. How many corn can be planted in this field?
( 15+24)x 18 # 2 = 35 1 m2
35 1X9=3 195 strain
A: This land can grow 3 159 maize plants.
12: The number of students in a class is less than 100. When waiting in line, there is just one more person in each row of 5, 4 or 3 people. How many people are there in this class?
5X4X3=60 people 60+ 1=6 1 person
A: There are 6 1 person in this class.
13: Wang Yue has a box of chocolate candy. The number of chocolates every 7, 5 and 3 is 1. How many chocolates are there in this box?
7X5X3= 105 capsules 105+ 1= 106 capsules.
There are at least 106 chocolates in this box.
14: There is a rectangular tunnel with a length of 15 m and a width of 1.2 m in Chenguang Community, which needs to be paved with square bricks. The designer prepared a square brick with a side length of 30 cm. Please calculate: how many such bricks are needed? If each square brick is 3 yuan, how much will it cost to build this tunnel?
15m = 150 decimeter 1.2m = 12 decimeter 30cm =3 decimeter.
150x12 =1800 square decimeter 3X3=9 square decimeter.
1800#9=200 yuan 200X3=600 yuan.
Answer: We need 200 such square bricks, and we need 600 yuan.
15: There are two parallelogram experimental fields with the same area. One is 70 meters long, 45 meters high and the other is 90 meters long. What's your height?
70x 45 = 3 150 m2 3 150 # 90 = 35m。
A: The height is 35 meters.
16: A batch of steel pipes are piled into a pile, with the bottom layer 10, the top layer 1 less 1 less, and the top layer 1 less. How many steel pipes are there in this batch?
10-5+ 1=6 floors (10+5)X6#2
= 15X6#2
=90#2
=45 pieces
A: There are 45 steel pipes in this batch.
Wait.-And-
1. A cuboid reservoir will be built in Gaodong Village with a planned storage capacity of 720 tons. It is known that the pool is 18 meters long, 8 meters wide and at least how many meters deep? (1 m3 water weight 1 ton. ) (equation solving)
2. Rectangular swimming pool, 50 meters long and 25 meters wide, with original water depth of 1.2 meters. If water is pumped, it will drain 2.5 cubic meters per minute. How many hours will it take to complete the drainage?
3. The bottom area of a cuboid fuel tank is 16 square decimeter and the height is 6 decimeter. If 1 liter contains 0.74 kg of gasoline, how many kg of gasoline can this tank hold?
4. Stack 2 100 cubes with side length of 1 cm into a cuboid. Its height is 1 decimeter, and its length and width are greater than its height. How long and wide is it?
The first question:
Solution: the depth is at least x meters.
18*8X=720
144X=720
X=5
The depth is at least 5 meters.
The second question:
50*25* 1.2= 1500 (m3)
1500/25=600 (minutes)
600 minutes = 10 hour
A: It takes 10 hour.
The third question:
16*6=96 cubic meters =96 liters
96 * 0.74 = 7 1.04kg。
A: This oil drum can hold 7 1.04 kg.
The fourth question:
1 decimeter = 10/0cm
2100/10 = 210 (cm)
210/70 = 3cm or 210/30 = 70cm.
A: The length is 70 cm; The width is 3 cm; Or a length of 30; The width is 7 cm.
Question 5:
There is a cube with a side length of 2 cm. What is the surface area of this cube?
Answer: 2*2*6=24 (square centimeter)
Question 6:
There is a cuboid with a length of 2 cm, a height of 2 cm and a width of 1 cm. What is the surface area?
Answer: (2 * 2+2 *1+2 *1) * 2 =16 (square centimeter).
Question 7: A rectangular board is 2m long, 5m wide and 8m thick. What is its surface area? How many cubic meters is the volume?
Answer: Surface area: (2*5+2*8+5*8)*2= 132 (square meter).
Volume: 2*5*8=80 (m3)
Channel 8: The side length of a cubic oil drum is 0.8 meters. How many liters is its volume? How many square decimeters does it take to make this oil drum and collect iron pieces?
0.8*0.8*0.8=0.5 12 (square meter) =5 12 (liter)
0.8*0.8*6=3.084 (square meter) =348 (square decimeter)
Lane 9: There are three sticks, which are12cm, 44cm and 56cm long. All should be cut into small sticks of the same length, and no extra ones are allowed. How long can each stick be?
Answer: What we are seeking here is the greatest common divisor of12,44,56! Do the math yourself!
Question 10: How much glass does a cubic fish tank without a cover need, which is 50 cm long?
Answer: 50*50*5= 12500 (square centimeter)
Question 1 1: A bag of candy can be divided into 8 people or 10 people, which is just right. How many pieces are there in this bag of sweets?
Answer: Here is the least common multiple of 8 and 10.
Question 12: There is a box of milk. Is it divided among five people or seven people? There is only one bottle left. How many bottles are there in this box?
Answer: What is found here is that the least common multiple of 5 and 7 is 1 on+.
Question 13: The rectangular land is 40 meters long and 45 meters wide, which is equal to the area of another parallelogram with a base length of 75 meters. What is the height of this parallelogram land?
Answer: 40*45= 1800 (square meter)
1800/75=24 (m)
Question 14: The area of a triangle is 3.4 square meters. What is the area of a parallelogram with the same height as it?
Answer: 3.4*2=6.8 (square meters)
Question 15: The rectangular pool is 8.5m long, 4m wide and1.5m deep. What is the area of this swimming pool?
Answer: 8.5*4=34 (square meters)
Question 16: A rectangular wooden box is 12 decimeter long, 8 decimeters wide and 6.5 decimeters high. If its shell is painted, how many square decimeters is the painted area?
Answer:12 * 8+(12 * 6.5+8 * 6.5) * 2 = 356 (square decimeter).
Question 17: The trapezoid has an upper bottom of 5m, a lower bottom of12m and a height of 8m. What is its area?
Answer: (5+ 12)*8=68 (square meters)
Question 18: The box made of rectangular parallelepiped is 0.8m long, 0.6m wide and 0.4m high. How much material does it take to make this box?
Answer: (0.9*0.6+0.6*0.4+0.9*0.4)*2=228 (square meter)
Question 19: The side length of a cubic carton is 0.6m.. How much material does it take to make a carton?
Answer: 0.6*0.6*6=2. 16 (square meter)
Question 20: The school in Li Xiaoming is1000m. He walks 100 meters per minute. How many hours does it take to get back to school?
Answer:1000/100 =10 (minutes) = 1/6 hours 2 1. The greatest common factor of two numbers is 30, and their least common multiple is 180. One of them is known as 65438+.
Answer: 30
22. From one end of the playground to the other, the total length is 96 meters. Originally, a small red flag was inserted every 4 meters from one end to the other. Now it has to be inserted every 6 meters. How many little red flags are there?
Answer: Because the total length of the sports ground is 96, there are 1 red flags every 4 meters. We can know that 4 is divided by 96 = 24, and because it is changed to 34 = 1226 = 12 every 6 meters, two red flags are pulled out every 4 sides, and 24 is divided by 2= 12.
23. There are 25 peaches and 75 oranges, which are distributed to several children. Everyone is required to share the same number of peaches and oranges, so how many children can I give at most? How many peaches does each child get? How many oranges?
Answer: (25,75) = 25 (25 is the greatest common divisor of 25 and 75).
25/25= 1
75/25=3
It can be distributed to 25 children at most, and each child gets 1 peach and 3 oranges.
24. Lan Lan's parents work in other places, and she lives in her grandmother's house. My mother visits her once every six days, and my father travels a long way, only once every nine days. Please think about it, at least a few days, mom and dad can come to see her at the same time. How many times can their family get together every two months?
Answer: (6,9) = 18 days (18 is the least common multiple of 6 and 9).
60/ 18=3 times ... 6 days
At least 18 days, mom and dad can visit her at the same time, and their whole family can get together three times in two months.
25. Buses run every 6 minutes. 15 runs every 8 minutes, and bus No.9 runs every 12 minutes. Now, three buses start from the starting point at the same time, at least in a few minutes, three buses start at the same time.
Answer: 6=2*3
8=2*2*2
12=2*3*2
3*2*2*2=24
26.72 The greatest common factor of decimeter length and 48 decimeter width is 24 decimeter, and the side length of the square tablecloth cut into the largest area is 2.4 decimeter.
Answer: (72÷24)×(48÷24)=3×2=6.
You can cut six pieces.
27. Aunt watered the roses and Clivia at the same time today. Roses are watered every four days, and Clivia is watered every six days. How many days have passed at least, and two flowers are watered at the same time?
Answer; Find the least common multiple of 4 and 6, which is equal to 24 days.
28. There are 30 cakes and 36 oranges, which are distributed to several children. Everyone gets the same income. How many children can you allocate at most?
Answer: Find the greatest common divisor of 30 and 36, which is equal to 6.
29.50 kg of rice, 60 kg of rice, 90 kg of rice, packed in several bags, all kinds of rice have just been eaten. What is the maximum weight of each bag?
Answer: Find the greatest common divisor of 50.60 and 90, which is equal to 10.
30. Make a bouquet with 24 red flowers, 36 yellow flowers and 48 purple flowers, so there are as many flowers in the bouquet. How many bunches can these flowers make at most?
Answer: Find the greatest common divisor of 24.36 and 48, which is equal to 12.
3 1. There is a cuboid whose width is three times the height, and the sum of the length of width and height is equal to the length. Now cut horizontally and vertically to get four small cuboids, and the surface area has increased by 200 square centimeters. What is the volume of the original cuboid?
Answer: Let the height be a, the width be 3a and the length be 4a.
Then the surface area increased by 2*3a*4a after crosscutting.
After vertical cutting, the surface area increased by 2*a*3a.
24a^2+6a^2=200
a=(20/3)^0.5
Volume v =12a3 =160/3 * (15) 0.5.
32. A rectangular fish tank without a cover is 0.4m long, 0.25m wide and 0.3m deep. How many square meters of glass does it take to make this fish tank?
Answer: 0.4×0.25+2×0.25×0.3+0.4×0.3.
=0. 1+0. 15+0.24
=0.49㎡
33. Fold a cube frame with 36 cm wire. What is the side length of this cube? If the surface of the frame is covered with paper, how many square centimeters of paper is needed at least?
Answer: 36 12 = 3 ㎝
6×3×3
=54 square centimeters
34. A rectangle with square base and sides. The height of a cuboid is 8 decimeters, and its volume is.
Answer:
Height of cuboid = perimeter of bottom =8 decimeters.
The side length of the bottom of a cuboid =8÷4=2 (decimeter)
Volume = bottom area × height =2×2×8=32 (cubic decimeter)
35. 12 candy, distributed to three people on average, how many of these sweets did each person get?
12/3= 12/3
36. Three identical cubes are spliced into a cuboid, and the surface area is reduced by120cm2. What is the surface area of the mosaic cube?
Answer: 120÷4=30 (square centimeter)
3×4×+ 1×2= 14 cube area.
14×30=420 (square centimeter)
30×6×3=540 (square centimeter)
37. Fill a rectangular water tank with a length of 24, a width of 9 and a height of 8 with 6 depths of water, and then put a cubic iron block with a length of 5. How much did the water level rise?
Answer: 5×5×5(24×9)
= 125÷2 16
≈0.5787
38. The sum of all sides of a cube is 84 cm. How many cubic centimeters is its volume? How many square centimeters is the bottom area?
Answer: 84/ 12=7 (cm)
Volume: 7*7*7= 343 (cubic centimeter)
Bottom area: 7*7=49 (square centimeter)
39. A section of road was built. On the first day, the full-length 1/4 was built, and on the second day, it was 90 meters. At this time, there is still150m left. How long is this road?
The answer is: this road is x meters long.
1/4X+90+ 150=X
X- 1/4X=90+ 150
3/4X=240
X=320
There is a pile of yellow sand on the construction site, and two-thirds of it is used, which is exactly 60 tons. How many tons is this pile of yellow sand?
Answer 60/2/3=90 (tons)
4 1 With 5000 kg of wheat, 4250 kg of flour can be ground, and the flour yield of wheat can be obtained.
Answer 4250/5000 * 100% = 85%
Wheat flour yield is 80%. How many kilograms of wheat does it take to grind 640 kilograms of flour?
Answer 640/80% = 800 (kg)
Teacher Wang went to the sporting goods store to buy five small soccer balls, spent 100 yuan and got back 32.5 yuan. How much is each small football?
Answer (100-32.5)/5= 13.5 (yuan)
I bought 25kg of Chinese cabbage for the first time and175kg of Chinese cabbage in the canteen for the second time. According to the calculation of 6 cents per catty of cabbage, how much does it cost to buy cabbage in the canteen?
Answer (25+ 175)*6= 1200 (angle) = 120 (yuan)
Xiaohua showed Xiaogang a book. Xiaohua read 132 pages in 4 days and Xiaogang read 96 pages in 3 days. Who reads fast? Why?
The answer is Xiaohua, look fast!
Because Xiaohua: 132/4=33 (page)
Xiaogang: 96/3=32 (page)
There used to be 72 basketballs in the sporting goods store, but two thirds of them were sold and 45 were bought. How many basketballs are there now?
Answer 72*2/3=48 (only)
72-48=24 (only)
24+45=70 (only)
The length of a cuboid is 0.54 meters, which is 8 centimeters more than the width and 5 centimeters higher. What is the area of this cuboid?
The answer is 0.54m = 54cm.
54-8=46 cm
54*46*5= 12420 cm2 = 1.242 m2
A steel bar 1 meter long, 2/5 meters was cut off. How many meters are left?
Answer 1-2/5=3/5 meters.
The orchard plans to use 2/5 peach trees, 2 pear trees 1/3 and the rest apple trees. What percentage of apple trees are there?
The answer1-(2/5+1/3) = 4/15.
A rectangular swimming pool is 5 meters long and 3 times wide. How many meters wide is it?
Answer 5 * 3 =15m. That's it! Hope to adopt