Xiao Ming's mother bought back some oranges. Xiao Ming ate half and half of them on the first day, the rest on the second day, and the rest on the third day. How many oranges did his mother buy? If you hurry up, I'll score + 40

Xiao Ming's mother bought back some oranges. Xiao Ming ate half and half of them on the first day, the rest on the second day, and the rest on the third day. How many oranges did his mother buy? If you hurry up, I'll score + 40

Day 3: 1
The next day: 2
First day: 4
Mom bought a total of: 4 + 2 + 1 = 7

The total cost of a and B goods is 2200 yuan. A goods are priced at 20% profit and B goods are priced at 15% profit. Later, according to the market situation, they are sold at 90% profit. The total profit is 131 yuan. What are the profits of a and B goods?

Suppose the cost of a is x yuan, then B is 2200-x yuan, then: 90% × [(1 + 20%) x + (2200-x) × (1 + 15%)] - 2200 = 131, 0.9 × [1.2x + 2200 × 1.15-1.15x] - 2200 = 131, 0.9 × [0.05x + 2530] - 2200 = 131, 0.045x + 2277-2200 = 131, 0.045x + 77 = 131, x = 1200

The school bus of the kindergarten starts from the kindergarten every morning and arrives at the station of Xinxin community at 8 o'clock sharp to pick up the children to go to the kindergarten. One day, the children start from the station of Xinxin community at 7:40 and walk to the kindergarten. When they meet the car on the road, they get on the car and go to the kindergarten. As a result, they arrive four minutes earlier than usual?

Four minutes earlier, that is to say, the car picked up the children two minutes away from the station
So the speed of the car is (8:00-7:40) / (4 / 2) = 10 times that of the children

For a project, if the first, second and third teams work together, it will take 8 days to complete; if the second, third and fourth teams work together, it will take 10 days to complete; if the first and fourth teams work together, it will take 15 days to complete. If each team works one day in turn in the order of 1, 2, 3, 4, 1, 2, 3 and 4, which team will complete the project last?

Because it takes 8 days for the first, second and third teams to work together; it takes 10 days for the second, third and fourth teams to work together; it takes 15 days for the first and fourth teams to work together?

1. (2 * 5) 1 + (5 * 8) 1 + (8 * 11) 1 + (98 * 101) 1 / 2 =?
2. (2 + quarter * 1) + (2 + quarter * 2) + (2 + quarter * 3) + (2 + quarter * 11)
3. If two thirds, four ninths and eight fifths of three fractions are removed by the same fraction, and the quotient obtained is an integer, what is the maximum fraction as a divisor?
4. Calculate the integral part of 9 / 10 + 99 / 99 + 99 / 99 + 10 million

1、=(1/3)[3/(2×5)＋3/(5×8)＋… ]=(1/3)[(1/2)－1/(101)]
2、=[2＋2＋… ＋2]＋(1/4)[1＋2＋… ＋11]
3. 2 / 3 = 30 / 45, 4 / 9 = 20 / 45, 8 / 15 = 24 / 45, then the number is 45
4、=[1－(1/10)]＋[1－(1/100)]＋… + [1 - (1 / 100000000)] = 10-0.000, the integral part is 9

Please add + or - sign before 1, 2, 2004, 2005 to minimize the absolute value of their sum

Except for 1
Every four adjacent numbers are a group,
+2-3-4+5＝0,
+6-7-8+9＝0,
+2002-2003-2004+2005=0
The absolute value of their sum is 1

A batch of 490 tons cargo is allocated to ship a and ship B for transportation. Now ship a and ship B carry 5 / 7 and 3 / 7 of their tasks respectively. Among the cargo already carried, ship a carries 30 tons more than ship B. what are the tasks allocated to ship a and ship B?

Let a task X and B task 490-x
The equation is: X * 5 / 7-30 = (490-x) * 3 / 7
8x/7=240
x=210
490-x=280

1. Given a = 3b, C = A / 2, find the value of a + B + C / A + b-c
2. Given A-B / A + B = 3, find the value of {2 (a + b) / A-B} - {4 (a-b) / 3 (a + b)}
3. Given XY / (XY) = 6, find the value of [3x-2xy + 3Y] / [- x + 3xy-y]
4. Given a / (X-Y) = B / (Y-Z) = C / (z-x), find the value of a + B + C
5. Given the square of M + M-1 = 0, find the cubic of M + the square of 2m + 2007
(in the question, "/" stands for the fraction line)
The problem is a little difficult, please think about it! Don't have a single result!
The third question is wrong
Given XY / x + y = 6, find the value of 3x-2xy + 3Y / - x + 3xy-y

1. (a + B + C) / (a + B-C) = (a + B-C + 2C) / (a + B-C) = 1 + 2C / (a + B-C) = 1 + 1 / ((a + B-C) / 2C), that is to say, (a + B-C) / 2C can be obtained
(a + B-C) / 2C is known and easy to find when it is divided into three terms
2.a-b/a+b=3=>a+b/a-b=1/3
The first half is equal to 2 * (1 / 3), and the second half is equal to (4 / 3) * 3
Required = 2 / 3 + 6 / 9
3. I suspect that your brackets are wrong. I don't understand the known conditions
No more
Method 1: there is no XYZ in the solution of this problem. It means that the value of root ZYX doesn't matter. Let XYZ get any number, and then solve three original first-order equations
The answer is 0
5: According to the known m-square + M-1 = 0 = > m-square + 2m + 1 = m + 2 = > (M + 1) square = m + 2
The formula is m cube + 2m cube + m + 2007-m
=M (M + 1) cube + 2007-m
Bring in the known
=m(m+2)+2007-m
=M + m + 2007
Bring in the known
=2008

If every inner angle of a convex polygon is equal to 140 degrees, then the polygon has a total of () diagonals. 3. There is a string of numbers, - 2003, - 1999, - 1995, - 1991. Then the sum of the first () numbers in the string is the smallest. 4. Select five of the 10 natural numbers from 0 to 9 to form five digits, so that the five digits can be replaced by 3, 5, 7, 7, The largest number is ()

1、 2.439458880924 * 1044 2. We know that the formula of the sum of the inner angles of a polygon is (n-2) * 180. Because each angle is 140 degrees, 140x = 180x-360x = 9. It is a 9-sided shape, that is, 8 + 7 + 6 + 5 + 4 + 3 + 2 + 1 = 36

Don't write in vernacular, just calculate
I'll make it up
PS: if there are mistakes in the questions, then answer them according to your own understanding. I moved down what was written on the test paper intact, and there may be mistakes. You can remove a few words or add a few words by yourself, and just do it according to your own understanding,
In addition, there are many questions. If you can't answer that column, you can send me a message
1. The sum of the numbers in one digit is 34. How many are there altogether?
2. Add a 0 between two digits of a two digit number, and add the three digits to the original two digits. The sum is 1002, so as to find the original two digits
3. A subtraction problem, the sum of the numbers on the subtracted members is 37, and the sum of the numbers on the subtracted members is 25. If the sum of the difference between the subtracted and the subtracted is 39, how many times do you abdicate in the process of subtraction?
4. The sum of number a and number B can be divided by 11. When the two numbers are added together, the sum of number a and number B is 6. What is the minimum difference between number a and number B?
5. Give a bag of small toys to several children. If you give 7 toys to one child, the rest of the toys will get 3; if you give 3 toys to three children, the rest of the toys will get 4. How many toys are there in this bag
6. Divide some oranges and oranges into bags. If there are 6 oranges and 5 oranges in each bag, there are 3 oranges left; if there are 8 oranges and 6 oranges in each bag, there are 18 oranges left. How many oranges and oranges are there?
7. Uncle Chen rides a bicycle from place a to place B, 10 kilometers per hour, arriving at 1 pm; 15 kilometers per hour, arriving at 11 am. He wants to arrive at 12 noon, how many kilometers per hour?
8. All the roads from a to B are uphill and downhill, of which the uphill road is twice as long as the downhill road. The speed of a car from a to B on the uphill road is half of that on the downhill road. It takes 1.5 hours to get there. How many hours does it take to return from B to a?
9. Remove the decimal point of a decimal and add it to 4 times of the original number. The sum is 702 to find the original decimal
10. After the decimal point between two numbers of an integer, add the decimal and the original integer. The sum is 10063.64. What is the original integer?
11. There are four boxes of fruits. It is known that there are 42 apples, pears and oranges in each box on average, 36 pears, oranges and peaches in each box on average. There are 37 apples and peaches in each box on average. How many apples in a box? How many peaches in a box?
12. In one examination, the average score of the three students is 91, the average score of the three students is 89, the average score of the two students is 95, and what are the scores of the two students?
13. The average of the five numbers is 18. After changing one of them to 6, the average of the five numbers is 16. What is the original number of this change?
14. Sort the five numbers from small to large. The average number is 38. The average number of the first three numbers is 27. The average number of the last three numbers is 48. What is the middle number?
15. Find arithmetic sequence 3, 7, 11 643
16. Xiaoming travels three hours an hour when he goes up the mountain and five kilometers an hour when he returns from the original road. What's the average speed of Xiaoming's round trip?
17. There is a square lawn. Build a one meter wide path along the lawn. The road surface area is 80 square meters
18. There are six classes in grade five, and the number of students in each class is equal. 16 students are selected from each class to participate in the young pioneers' activities. The remaining students are equivalent to the number of the original four classes. How many students are in each class?
19. The sum of two digits of a two digit number is 10. If the two digits of this two digit number are transposed to form a new two digit number, it will be 72 times larger than the original number
20. For a two digit number, the number in the ten digit number is three times of the number in the one digit number. If the two digits are offset to form a new two digit number, and the original number is 54
21. For a two digit number, the number in the ten digit number is twice the number in the one digit number. If the two digits are transposed to form a new two digit number, and the sum of the original two digits is 132, the original number can be obtained
If the two numbers are transposed to form a new two digit number, and the sum of the original number is 154, find the original number
[23. Xiao Ming can only drive one cow at a time on the back of a cow to cross the river. There are four cows, a, B, C, and D. It takes one minute for a cow to cross the river, two minutes for B cow, five minutes for C cow, and six minutes for D cow. It takes at least () minutes to feel the other side of the river.] "this problem is quite special. You don't need to make a formula, but please explain it in vernacular."
I'm sorry, there are some mistakes in some questions
1. The number in "each" digit

15. Too much... Arithmetic 3, 7, 11 What's the average speed of Xiaoming's round trip? Suppose: it takes x hours to go up the mountain and Y hours to go down the mountain