Suppose the speed of A is X km/h and the speed of B is (X-2) km/h..
2(X+X-2)=36*2
2X=38
X= 19
19-2= 17
( 19+ 17)*2+36= 108
A: The speed of A is 19 km, that of B is 17 km, and that of AB is 108 km.
108/(19+17) = 3 hours.
Because of the second meeting, they ran three AB, so 3*3=9 hours.
A: The first meeting was at 8+3= 1 1, and the second meeting was at 8+9= 17, that is, at 5 pm.
1, and the walking speed ratio of Party A and Party B is 7: 5. They set out from A and B at the same time, face to face, and meet each other after 0.5 hours. If they start from A and B at the same time and go in the same direction, how many hours will it take for A to chase B?
2. Xiao Zhang cut a 3 cm wide strip from a square piece of paper, and then cut a 4 cm wide strip from the remaining rectangular piece of paper. If the area of the paper cut twice is exactly the same, what is the side length of the original square paper?
3. There are a flock of pigeons. Some of them are from singing in the trees, and some are foraging on the ground. A pigeon in the tree said to the pigeons on the ground, "If one of you flies, the pigeon in the tree is 1/3 of the whole flock. If a bird flies down from a tree, there are as many pigeons on the tree as there are under it. How many pigeons are there on and under the tree?
4. Xiao Li rode his bike from place A to place B, and Xiao Ming rode his bike from place B to place A, both of them made constant progress. It is known that they started at 8 o'clock in the morning. At the same time, the distance between 10 in the morning and 12 at noon is 36 kilometers. Find the distance between a and B.
1. If the speed of A is 7x, the speed of B is 5x and the distance of AB is s, then:
(7x+5x)* 0.5 = seconds
What I'm asking is
(7x-5x)*y=s
It is solved by two formulas:
y=3
So make it up in three hours.
2. Let the side length of the original square piece of paper be x.
3*x=(x-3)*4
3x=4x- 12
x= 12
So the original side length is 12cm.
3. Suppose there are X pigeons on the tree and Y pigeons under the tree.
de:X+ 1 = 3(Y- 1)( 1)
X- 1=Y+ 1 (2)
X=Y+2 (3) from (2)
Replace (3) with:
Y+2+ 1=3Y-3
6=3Y-Y
Y=3
Three under the tree and five on the tree.
4.
Suppose the AB distance is x, when x, 12-10 =2 hours, 10 -8 hours =2 hours.
2*[(36*2)/2]=X-36
The first two hours are from 8: 00 to 10, ***2 hours.
36*2 is from 10 to 12, which is 36 kilometers apart, that is, two people walked 36 * * 2 kilometers in two hours.
(36*2)/2 Find how many kilometers two people walk in an hour, which is the sum of their speeds.
According to the sentence "Know that two people start at 8 o'clock in the morning at the same time, and in the morning 10, they are still 36 kilometers apart", the equation is listed.
result
X= 108
If a green vegetable is produced in a certain place and sold directly in the market, the profit per ton is 1000 yuan; After rough machining, the profit per ton can reach 4500 yuan; After fine processing and sales, the profit per ton rose to 7500 yuan. A local agricultural and industrial company harvested 140 tons of this vegetable. The processing capacity of this company is: if vegetables are roughly processed, they can process 16 tons per day; If fine processing is carried out, 6 tons can be processed every day, but the two processing methods cannot be carried out at the same time. Due to seasonality and other conditions, the company must sell or process all these vegetables within 15. Therefore, the company has worked out three feasible schemes.
Scheme 1: complete the processing of all vegetables.
Scheme 2: Roughly process as many vegetables as possible, and the vegetables that are not processed in time are buried in the market and sold directly.
Scheme 3: Fine processing some vegetables and rough processing the rest, which was just completed on 15.
Which scheme do you think is the most profitable? Why?
Option 1:
Because 6* 15=90 140 tons, it can be treated in 15 days.
Get 4500* 140=630000 yuan.
Option 3:
Because the two methods cannot be carried out at the same time.
Therefore, it is assumed that it takes x days for finishing and 15-X days for rough machining.
So 6x+16 * (15-x) =140.
The solution is X= 10.
15-X=5
So you get 7500 * 6 *10+4500 *16 * 5 = 855000 yuan.
So option three is the best.
1. According to national regulations, the tax payment method of deposit interest is: interest tax = interest x20%, and depositors' withdrawals are withheld and remitted by banks. The annual interest rate of one-year time deposit in Norfolk Bank is 1.98%. When the depositor receives the principal and interest due in one year from the bank, the interest tax is deducted 198 yuan.
Q: 1 What is the principal deposited by the depositor?
2. What is the depositor's actual interest?
2. Since 2007, the government of China has provided living allowance to students in vocational middle schools, and each student has been subsidized by 1.500 yuan annually. It is estimated that the number of students in vocational secondary schools in 2008 will be 65,438+0.2 times that in 2007, and the investment will be increased by 6 million yuan on the basis of 2007. How many students were there in this city in 2008? How much is the subsidy?
(1) Interest: 198/(20%)=990 yuan.
Principal: 990/(1.98%) = 50,000 yuan.
(2) The interest earned is 990- 198=792 yuan.
(1) Let the principal be x.
Then (1.98%)x*20%= 198.
The solution is x=50000.
So the principal is 50 thousand.
(2) The interest due is 50,000 *1.98% * (1-20%) = 792 yuan.
2
In 2008, it was increased on the basis of 2007: 600,000/1500 = 4,000 (persons).
Number of students in vocational middle schools in 2008: 4000/(1.2-1) = 20000 (persons)
In 2008, how many vocational school students were there in this city: 20000* 1.2=24000 (person) =2.4 (person).
How much subsidy: 2.4 *1500 = 3,600 (ten thousand yuan)
Assuming that there were x vocational school students in 2007, there were 1.2x vocational school students in 2008.
According to the meaning of the question, it means1500x+600000 =1500 *1.2x.
The solution is x=20000.
Then 1.2x=24000.
24,000 people = 24,000 people
1500*24000=36000000 (yuan) =3600 (ten thousand yuan)
Therefore, in 2008, there were 24,000 vocational school students in the city, with a subsidy of 36 million yuan.
1. There are * * 834 people in two villages, and the number of people in village A is less than half of that in village B.11. How many people are there in each village?
2. A car and an electric car start from two places 298 kilometers apart. The speed is higher than the electric car 15km, and the two meet after half an hour. Find the speed of two cars.
3. Someone * * * spent 142 yuan bought 20 Jin of two kinds of fruits. It is known that 8 yuan per kilogram of Class A fruits and 6 yuan per kilogram of Class B fruits. How many kilograms are these two fruits?
4. Enclose a rectangle with an 80m-long rope so that its width is 1/3. What should its length and width be?
5. It takes 65,438+00 hours for a ship to sail between two docks, and 6 hours to sail downstream. It is known that the ship is sailing at the speed of 12 km per hour in still water, and the current speed and the distance between the two docks are calculated.
6. A project took Party A 20 days and Party B 10 days to complete. Now Party B has used it for a few days, and Party A has done the rest, and it has taken 12 days successively. How many days did Party B do it?
1, there are x people in village B.
1/2X- 1 1 1+X = 834
3/2X=945
X=630
630 ÷ 2-111= 204 (person)
A: There are 204 people in Village A and 630 people in Village B..
2. Set the speed of the electric car to X km/h. 。
0.5(X+6X+ 15)=298
3.5X+7.5=298
3.5 times =290.5
X=83
83× 6+ 15 = 5 13 (km/h)
Answer: The speed of electric cars is 83 km/h and that of cars is 513 km/h. 。
3, set a fruit x kg.
8X+6(20-X)= 142
8X+ 120-6X= 142
2X=22
X= 1 1
20- 1 1 = 9 (kg)
Answer: A fruit 1 1 kg, B fruit 9 kg.
4. Set the length to x meters.
2(X+ 1/3X)=80
8/3X=80
X=30
30 ÷ 3 = 10 (m)
A: It is 30m long and10m wide.
5. Let the speed of water be x km/h. 。
10( 12-X)= 6( 12+X)
120- 10X=72+6X
- 16X=-48
X=3
10 (12-3) = 90 (km)
Answer: When the water speed is 3km, the distance is 90km.
6. suppose b did it for x days.
1/ 10X+ 1/20( 12-X)= 1
2X+ 12-X=20
X=8
A: B did it for eight days.