Xiao Ming, Xiao Liang and Xiao Gang have played table tennis. Xiao Ming has played five games, Xiao Liang has played four games and Xiao Gang has played three games. How many games have these three children played in total? The specific calculation method is needed It's right to say this, say that, and say that

A total of 6 games have been played, because each game has two children participating, that is to say, each game of each child and a certain game of another child are the same game, so the total number of games is: (5 + 4 + 3) / 2 = 6

According to the measurement, the water in children's body accounts for 4 / 5 of their body weight. Xiaogang has 32 kg of water in his body. Xiaogang's father's weight is 15 / 8 of Xiaogang's weight
1. How many kilos does Xiao Gang weigh?
2. How many kilograms does Xiao Gang's father weigh?

1. Weight of Xiaogang = 32 △ 4 / 5 = 40 (kg)
2. Father's weight = 40 × 15 / 8 = 75 (kg)

Xiaoming, Xiaoliang, Xiaogang and Xiaoying work together to study a mathematical problem. As shown in the figure, if EF ⊥ AB and CD ⊥ AB are known, Xiaoming says, "if you also know ∠ CDG = ∠ BFE, you can get ∠ AGD = ∠ ACB." Xiaoliang says, "turn Xiaoming's known and conclusion upside down, that is, ∠ AGD = ∠ ACB, you can get ∠ CDG = ∠ BFE." Of the four of them, () are right
A. 1B. 2C. 3D. 4

It is known that EF ⊥ AB, CD ⊥ AB, ∥ CD ∥ EF, (1) if ∠ CDG = ∠ BFE, ∥ BCD = ∠ BFE, ∥ BCD = ∠ CDG, ∥ DG ∥ BC, ∥ AGD = ∠ ACB, (2) if ∠ AGD = ∠ ACB, ∥ DG ∥ BC, ∥ BCD = ∠ CDG, ∥ BCD = ∠ BFE, (3) if ∥ DG is not necessarily parallel to BC, so ∠ AGD is not necessarily greater than ∠ BFE; (4) if GF is connected, GF is not necessarily parallel to BC To sum up, there are two correct statements

To complete a project, the daily work efficiency of team a is equal to the sum of the daily work efficiency of team B and team C, and the work efficiency of team C is equivalent to 15% of the daily work efficiency of team a and team B. if the three teams can complete the project in 8 days, how many days does it take team B to complete it alone?

A: it takes 24 days for a single person to copy

After the price of a commodity has been raised by one tenth, it has been reduced by one tenth. Is the current price the original price?

Now the price is 99% of the original price
Suppose that the original price is x, the price increase becomes (x + 1 / 10x) and the price decrease becomes (x + 1 / 10x) * 9 / 10
Then divide by the original price x to get [(x + 1 / 10x) * 9 / 10] / x = 99 / 100 where the price is the original price
So now the price is 99% of the original price

(- 1 by 1 / 2) + (- 1 / 2 by 1 / 3) + (- 1 / 3 by 1 / 4) +. + (- 1 / 2010 by 1 / 2011) how much is it

It's equal to 1. Do you want to share more

Solving mathematical problems with equations
In a cage, there are chickens and rabbits. Counting their feet, there are 20 in total. How many chickens and rabbits are there in the cage
There are eight

Suppose there are x rabbits, then there are (8-x) chickens
4x+2（8-x）=20
4x+16-2x=20
2x=20-16
2x=4
x=2
Chicken: 8-2 = 6

1. There are 45 people in the class. In one election of monitor, there are three candidates: A, B and C. in the election process, one can not abstain. When counting the first 37 votes, we find that a has 17 votes and B has 5 votes. How many more votes can a get before he is elected?
2. Use a 18cm long and 14cm wide rectangular iron sheet, cut off four small squares on the four corners, and fold it into a uncovered rectangular iron box. If the length, width and height of the iron box are all integers, what is the maximum volume of the iron box?
3. There is a column of numbers: 2,1,1,2 The rule is: three times of each number from the second number is equal to the sum of the two numbers before and after it. Then what is the remainder of the hundredth number divided by three?

In the first 37 ballots, it is found that a has 17 ballots, B has 5 ballots, C has 15 ballots, a total of (45-5) / 2 = 20 ballots. If there are more than 20 ballots, a can get 4 more ballots. 2. If the company commander of a square is x, the closer the values of (18-2x) and (14-2x) are to x, the larger their volume is

7.044 billion yuan, 291 million tons in scientific notation and 291 million tons in scientific notation

7.044*10＾9
2.91*10＾8

It's all about it

You have a book called it has a very comprehensive polyphony, there are other very helpful knowledge!

According to the measurement, the water in children's body accounts for 4 / 5 of their body weight. Xiaogang has 32 kg of water in his body. Xiaogang's father's weight is 15 / 8 of Xiaogang's weight 1. How many kilos does Xiao Gang weigh? 2. How many kilograms does Xiao Gang's father weigh?