There are 360 students in the sixth grade of a school, of which the number of boys is 80% of the number of girls. How many boys and girls are there respectively?

360 × 8080 + 100 = 160, 360-160 = 200; answer: there are 160 boys and 200 girls

There are 360 students in Grade 6 of a school, 80% of whom are boys. How many are boys and girls?

Set girls as X
x+80%x=360
1.8x=360
x=200
Male: 360-200 = 160 or 200 * 80% = 160

There are 360 students in the sixth grade of Guangming primary school, among which 712 are girls. Later, several girls are transferred. In this way, girls account for 60% of the total number of sixth grade students. How many girls are transferred?

360 × (1-712) △ 1-60%) - 360 = 360 × 512 △ 40% - 360 = 150 △ 40% - 360 = 375-360 = 15 (people) a: there are 15 girls transferred

There are 40 students in class 1, 28 students in class 2, 42 students in class 2, 34 students in class 3 and 38 students in class 3
The PE standard rate of each class and the PE standard rate of grade 6 are calculated respectively

First class = 28 △ 40 = 70%
Class 2 = 34 △ 34 ≈ 81%
How many people have reached the standard in class three?

There were 28 students in class 6 (2), of which 3 / 4 were boys. Later, several boys were transferred to this class, which was 1 / 2 of the class,
OK, I'll give you more points

1. Set the original number of girls as X;;
2. X+3/4*X=28；
X=16
The original male should be 3 / 4 * x = 12;
3. Suppose that the number of boys who have transferred in later is y;
This is that male students account for 1 / 2 of the class, that is, male and female students each account for 1.5%;
Y+12=16;
Y=4
So the number of boys transferred is four

Class (1) class (2) class (3) class (4) class (5) class 39 41 40 43 42 which classes can be equally divided into the same number of groups? Which classes are not allowed? Why? (more than one person in each group and more than one group are required.)

39, 40 and 42 are combined numbers and can be divided into groups with the same number on average; 41 and 43 are prime numbers and can not be divided into groups with the same number on average. Answer: (1) class, (3) class, (5) class can be divided into groups with the same number on average; (2) class, (4) class can not be divided into groups with the same number on average

What are the solutes and solvents for alcohol disinfection

There's nothing else. It's an aqueous solution of alcohol,
The solute is alcohol and the solvent is water
The normal concentration is 75%

It is known that hydrogen accounts for 0.12 in an alcohol solution, and the mass fraction of solute can be calculated

∵ mass fraction of hydrogen in ethanol = 6 / (12 * 2 + 6 + 16) = 0.13043
Let the mass of solute in 100g solution be X
(0.13043x)/100 =0.12
∴x=92g
The mass fraction of solute = 92 / 100 * 100% = 92%

200 g of 60% alcohol solution and 300 g of 30% alcohol solution, what is the mass fraction of solute in the alcohol solution? Before 11 o'clock

The mass fraction of solute in the obtained alcohol solution is
（200g×60％+300g×30％）/（200g+300g）×100%=42%
A: the mass fraction of solute in the mixed alcohol solution is 42%

Calculate the mass fraction of hydrogen in 50% alcohol solution

Let the solution be 100g
50% alcohol solution: 50g ethanol, 50g water,
The mass fraction of hydrogen is the total mass fraction of hydrogen in ethanol and water
( 50*6/46 + 50*2/18 )/100

There are 360 students in the sixth grade of a school, of which the number of boys is 80% of the number of girls. How many boys and girls are there respectively?