2. Add conditions or questions according to the formula.
(1) There are two ropes, one is 23 meters long, how long is the second one?
①23 × 13 ; ②23 + 13
③23 ×( 1- 13 ) ; ④23 ×( 1+ 13 )
(2) A book has 100 pages. How many pages have you read?
100× 15 ; 100×( 1- 15 )
(3) A 400-meter road has been built 15.
400× 15 ; 400×( 1- 15 )
(4) bright primary school planned to plant 1200 trees. As a result, 58 trees were planted for the first time and 35 trees were planted for the second time.
① 1200×35
② 1200×(58 -35 )
③ 1200×(58 +35 - 1)
4, () is 45 of 40; 40 is 45 of ()
More than 20 kg 14 is () kg; 20kg is smaller than () 15
5. A pile of coal weighs 45 tons, and it takes 10 hour for a truck to transport it. Then, it will take 4 hours to finish the work.
It will take () hours to finish this task.
6. From place A to place B, car A needs 10 hour, car B needs 15 hour, and the speed ratio between car A and car B is (). At this speed, the time ratio between car A and car B is ().
7. A rope is 5 meters long and divided into 8 parts on average. Each part is meters long, and each part accounts for the whole length.
8. Enlarge the former item of a ratio by 2 times and reduce the latter item by 2 times, and the ratio is ().
9. A rice mill can grind into tons of rice per hour, 1 hour can grind into () tons of rice, and 1 ton of rice takes () hours.
10, and the ratio of side lengths of two cubes is 3: 2; The ratio of the surface areas of large and small cubes is (); The volume ratio of large and small cubes is ().
1 1, 1 ton rapeseed can squeeze tons of oil, 140 ton soybean can squeeze tons of oil; It takes () tons of soybeans to squeeze 140 tons of oil.
12. A bucket of water can fill 10 bowls or 12 cups. Pour 5 cups of water and 3 bowls of water into the empty bucket, and the water level accounts for () () of the bucket height.
13、( )20 =20÷( )=8:( )=0.8=( )%
After 14 and 120 are increased by 15%, it is (). () Less than 60 10%.
15, 45 meters is 90 meters ()% 5 tons is 500 kilograms ()%,
() is 80% of 20m () is more than 8, 10%, and 4 hours is less than 20% of ().
16, the oil yield of one rapeseed is 35%, 400 kg rapeseed can extract () kg oil, and it takes () kg rapeseed to extract 1400 kg oil.
17, (): 20= 12() =24÷( )=( )%= 20% = () fold.
18. Add () kg of water to 30 kg of salt, and you can get brine with a salt content of 30%.
Processing a farm tool, once every 80 yuan, now every 64 yuan. How much is the cost reduced?
(80-64)/80=
The railway from city A to city B is 2 16 kilometers long. A train starts from a city and travels 96 kilometers in the first two hours. At this rate, how many hours will it take to get to B city? 2 16/(96/2)=
For a project, it takes 10 hour for Party A to do it alone and 15 hour for Party B to do it alone. How many hours does it take two people to complete half of the project? 1/2/( 1/ 10+ 1/ 15)=
A workshop produced *** 1280 copies of A, B and C, in which the ratio of A to B was 3: 2, and C was 80 more than A. How many copies did C produce?
( 1280-80)*3/(3+2+3)+80=
9. After the weaving factory finishes processing a batch of cloth, it takes Party A 16 days to cooperate, 20 days for Party A to do it alone, and Party B has to weave 600 meters every day. How many kilometers is this batch of cloth?
10, Party A and Party B drive in the opposite direction from the same place. Party A leaves at 6: 00 p.m. at a speed of 40,000 meters per hour. Party B left at 4 am the next day. 10 hour later, the distance between the two cars is1080km. What's the speed of car B?
1 1. Machine tool factory manufactures a machine tool, and each machine tool uses 1.5 tons of steel, which actually saves 0.25 tons. As a result, 10 more machines were produced than originally planned. How many machine tools were originally planned?
12. Xiao Wang bought a batch of toothbrushes with a wholesale price of 0.35 yuan and a retail price of 0.40 yuan. When there were 200 toothbrushes left, Xiao Wang calculated that he had made a profit after deducting all the costs. How many toothbrushes did the shop buy?
13. Salt is completely dissolved in water and becomes brine. It is known that the weight ratio of salt to water in brine is1:10.500g of salt. How many kilograms of water should I add?
14, a highway was built, and 20% of it was built five days ago. According to this calculation, how many days will it take to complete this road?
15, the original price of a washing machine 1450 yuan, is now reduced by 20%, but the price is still higher than the cost 1/9. What is the price of this washing machine?
16. The actual investment in building a new road is10.588 million yuan, which is 210.20 million yuan less than the original plan. What percentage was saved?
17. it takes 10 hour for team a to complete a project alone, and 15 hour for team b. Now Team A has to work alone for 2 hours, while everyone else in Team B is working. How many hours will it take to finish this task?
18, Xiaolin goes to school from home at 7: 30 in the morning and walks 50 meters every minute. When I first arrived at the school gate, I found that I didn't bring my math book. I immediately went back the same way and walked 70 meters per minute. It was exactly 7: 54 when I got home. How many meters is Xiaolin's home from school?
19, a cuboid warehouse, about 9 meters long, 6 meters wide and 5 meters high from the inside. If you put it in a cubic wooden box with a side length of 2 meters, how many can you put at most?
20. The accountant of a factory found that the cash was 273.6 yuan more. After checking the accounts, I found that the decimal point of an expenditure was wrong. how much is it?
2 1. A paper mill carried out household saving activities, saving 1.44 tons of coal every day. If 3 kilograms of coal can generate 7.5 degrees of electricity, how many degrees of coal can be saved every day?
22. The decimal point of a certain number is shifted to the left by one place, which is 4 1.4 less than the original number. What was the original number?
23. The area of a triangle is18cm2, its base is12cm, and how many centimeters is its height?
24. If a box of soap is distributed to a workshop worker, the average person can get 12. If it is only distributed to female workers, the average person can get 20 yuan. If it is only distributed to male employees, how much can each person get?
25. The profit of a commodity is 20% of the cost. If the profit is increased to 30%, how much should the selling price be increased?
26. There is an oil mill that squeezes oil. 100 kg rapeseed can squeeze out 38 kg oil. How many kilograms of rapeseed does it take to squeeze 1 kg oil? 1 kg rapeseed can squeeze out how many kilograms of oil?
27. Fold the 48 cm long iron wire into a right triangle with the ratio of three sides of 3: 4: 5, and find the area of this right triangle.
28. Xiaohong's family has a barrel of oil, which weighs 8 kilograms. Half of it is used, and the barrel weighs 4.5 kilograms. How many kilograms of crude oil?
29. The area of rectangular flower beds is 6 square meters. If the length is increased by 1/3 and the width is increased by 1/4, how many square meters is the area now more than before?
9. Let A knit X every day.
(600+x)* 16=20x
600* 16+ 16x=20x
9600=20x- 16x
9600=4x
x=9600/4
x=2400
10,40000 * (28-18) =400000 (m) = 400 (km) 1080-400=680 (km) 680/10 =
A: B travels 28 kilometers per hour.
1 1. Set the original planned machine tool as X sets.
X * 1.5 =( 1.5-0.25)*(X+ 10)
Then X=50.
12,200/(0.4-0.35) = 4000 (branches) 4000+200=4200 (branches)
13500/0. 1 = 5000 (g)
14,5/20% = 25 (days)
15,1450 * (1-20%) =1160 (yuan)1160/(1)
16.158.8-21.2 =137.6 (ten thousand yuan)
137.6÷ 158.8≈86.6%
A: It saved 86.6% than planned.
17,2/10 =1/515 * (1-1/5) =12 (hours)
18 His average speed twice was 60 *** and he walked for 24 minutes on average 12 minutes.
So the home is 60* 12=720 meters away from school.
19, integer withdrawal, tail cutting method. 9/2=4,6/2=3,5/2=2.4*3*2=24.
20, 10X is 273.6 more than x.
That is 10X-X=273.6.
9X=273.6
X=30.4
2 1, 1.44 tons = 1440kg 7.5/3=2.5 degrees 1440*2.5=2650 degrees.
22、4 1.4/ (9/ 10)=46
23. 18*2=36 (cm)
36÷ 12=3 (cm)
Answer: The height is 3 cm.
24,1÷ (112-1/20) = 30 pieces.
25. If the cost is 1, the original selling price is (1+20%)= 1.2. If the profit is increased to 30%, the selling price is (1+30%) = 1.3-65438.
28: 8-4.5 = 3.5 (kg) Oil: 3.5 times 2=7 (kg)
26: 38 divided by 100=0.38 (kg) 100 divided by 38= 100/38=50/ 19 (kg).
27, 48*5/3+4+5=20 (cm) 48*4/ 12= 16 (cm) 48*3/ 12= 12 (cm)
12* 16/2=96 (square centimeter)
28, (8-4.5)x2=7 (kg)
29. If the original length x width y xy=6, the current area is (1+1/3) x * (1+1/4) y = 5/3xy =10.
Fill in the blanks. (3 points for each question)
1), divide a circle into several parts evenly, and then make a rectangle. The length of the rectangle is 9.42 decimeters, the width is () decimeters, and the area is () square decimeters.
There are only two questions in the math exam. There were 42 people who answered the first question correctly and 48 people who answered the second question correctly. Each of the 60 people in this class answered at least 1 question correctly, so the number of people who answered all two questions correctly accounted for () 3 of the class. There is a pool of water. When water freezes, its volume increases by L/ 165438. When ice becomes water, its volume decreases ()
4) There are natural numbers whose plus 1 is a multiple of 2, plus 2 is a multiple of 3, plus 3 is a multiple of 4, plus 4 is a multiple of 5, plus 5 is a multiple of 6, and plus 6 is a multiple of 7. The smallest of these natural numbers except 1 is _ _.
5), with 0, 1, 2, 3, 4, at least the number () can be composed of three non-repetitive digits.
6) There are 40 students in one class, including math group 15 and model airplane group 18, both of which are 10. Then there are () people who don't participate in both groups.
7) There is a rope with a length of 180 cm. Starting from one end, make a mark every 3 cm and 4 cm, and then cut it where there is a mark. Ask the rope to be cut into sections ().
8) The quotient of 50 divided by 7 has the fourth decimal place () and the thirtieth decimal place ().
9), a rectangle, if the height increases by 2cm, it becomes a square, then the surface area increases by 56 square decimeters, and the original cuboid volume is ().
10), the cuboid has a surface area of 3 14 square decimeter, a bottom area of 72 square decimeter, a bottom circumference of 34 decimeter and a volume of () cubic decimeter.
1 1), the surface area of the cube fish tank is 259.2 square decimeter, and the volume is () cubic decimeter.
12) Draw the largest square in a circle with a diameter of 10 cm, and the area of this square is () square cm.
13), the areas of three sides of a cuboid are 10 square decimeter, 15 square decimeter and 6 square decimeter respectively, so the volume of this cuboid is () cubic decimeter.
14), the known number A =2×a×3×7, the number B =2×3×b×5× 1 1, and A and B are coprime, and a≠b≠0 is the greatest common divisor of A and B.
15), two four-digit numbers A275 and 275B are multiplied so that their product energy can be divisible by 72. A is () and b is ().
16), the clock strikes 4 times at 4 o'clock and knocks out in 6 seconds; Then 12 points 12, () seconds to knock out.
17) Six regular triangles with a side length of 7 cm are spliced into a parallelogram, and the perimeter is reduced by () cm.
18) It is known that the ratio of the height of a cylinder to the radius of its bottom surface is 1: 2, and their volume ratio is (): ().
19) Huanhuan+Yingying+You = Welcome Huanhuan = () Yingying = () You = () Welcome you = ()
20) A box of eggs sold half the first time, the remaining half the second time, the remaining half the third time and the remaining half the fourth time. Finally, there are three eggs left in the box. There are () eggs in this box.
2. Solve problems (6 points for each question)
2 1), as shown in the figure, quadrilateral AB= 8cm CD=2cm, what is the area of quadrilateral ABCD?
22) A batch of grapes weighed 250kg when put into storage, and the measured water content was 99%. After a while, the water content was 96%. What is the weight of grapes at this time?
23) Party A and Party B walk opposite AB, meet at a distance of 600 meters from B, walk again, return after arriving at BA, and meet at a distance of 300 meters for the second time. What's the distance between AB and B?
24) For a water conservancy project, Party A works alone for 8 days, and Party B works alone for 4 days. With the cooperation of Party A, Party A takes a rest due to illness 1 day. How many days did Party B work when completing the task?
25) A cylindrical container, with a diameter of 8 decimeters from inside to outside, contains some water. Now use a graduated cylindrical rod with a length of 65,438+000 cm and a bottom circumference of 2.565,438+02 cm to measure that the water surface is 3 minutes away from the upper end of the container. Now, put a stone in it, then put the cylindrical rod into the water, show the scale of 6.5 decimeters, and find the volume of this stone.
26) After adding a certain amount of water to some salt water, the concentration of salt water decreased to 3%, and after adding the same amount of water, the concentration decreased to 2%. Q: How much does the concentration drop after adding the same amount of water?
27) The school bought four footballs and six volleyballs from Zhong Bai supermarket, and spent 660 yuan. Later, the unit price of football in supermarkets in Zhong Bai increased by 10%, and the unit price of volleyball was cheaper by 15%, so * * * needed 636 yuan. What is the original unit price of football and volleyball?
28) Two cars, A and B, travel in the opposite direction from A at the same time and enter B and C respectively. It is known that the distance between A and B is nine tenths of the distance between A and C. When A car travels 60km, the ratio of the distance traveled by B car to the remaining distance is 1: 3. At this point, the distance between the two cars and the destination is equal. How to find the distance between a and c?
29) The number of workers in the second workshop of a factory is 75% of that in the first workshop. After the first workshop recruited several workers, the number of workers in the first and second workshops was 7:4. After the second workshop recruited several workers, the number of workers in the first and second workshops was 9:8. It is known that the second workshop will recruit 5 more people. So how many people are there in Workshop 2?
30) A ball fell into a cylindrical water tank, and one third of its height surfaced. It is known that the diameter of the bottom inside the water tank is 8 decimeters, and now the water depth is 90 decimeters, and the diameter of the ball is 6 decimeters. Take the ball out, the water depth is 87 decimeters, and find the volume of the ball. (Sphere volume formula = pi * radius cube)