A sixth grade school held a Chinese and mathematics competition

A school held a Chinese and mathematics competition in the sixth grade, and the number of participants accounted for 40% of the total number of students in the whole grade.

The ratio of the number of students in the math competition is 8:15, and there are 12 students participating in both subjects, so how many students are there in the whole grade?

Solution: If there are at least x students in the whole grade, then 40%*x+12 is the sum of the total number of participants in Chinese and mathematics, because the ratio of the number of participants in Chinese and mathematics is 8:15, so 40%x+12 should be a multiple of (8+15), and because the 1 times of (8+15) is:

23,23*(8 23)=8<12, 2 times (8+15) is 46,46*(8 23)=16>12, so 40%x+12=46, solution: x=85 Answer: There are at least 85 students in the whole grade.

Let the number of participants be x, x*2 5+x*3 4-12=x x=80 The total number of participants is 80 40%=200 There are a total of x people Three-quarters of those who participate in the mathematics competition x those who participate in the language are.

There are 8x students in Chinese and 15x in mathematics.

The number of people in the whole year is:

8x+15x-12)/40%

5(23x-12)/2

115x/2-30

The number of people is an integer.

So x takes 2 at a minimum

That is, the minimum number of people is 115*2 2-30=85 people.

There are 8x students in Chinese and 15x in mathematics.

The number of people in the whole year is:

8x+15x-12)/40%

5(23x-12)/2

115x/2-30

The number of people is an integer.

So x takes 2 at a minimum

That is, the minimum number of people is 115*2 2-30=85 people.

Let's go for 450 people!

Here's what I thought :

Let's say there are x people in the race.

Languages participating: (2 5)*x

Participation in mathematics: (5 6) x

Then there is: +21=x

Solution: x=90

So: the total number of people is: 90 20% = 450

I don't know if it's true!

The number of participants in the language competition accounted for 40% of the participants, and the number of participants in the mathematics competition accounted for 75% of the participants

It can be seen that the number of participants in the two competitions accounts for the total number of participants: 40% + 75% = 115% Therefore, the number of participants in the bright event accounts for the number of participants: 115%-100% = 15% Therefore, the number of participants is: 12 15% = 80 (people).

Therefore the number of sixth graders is: 80 40% = 200 (people) and therefore c is correct.

12 (2 5 + 3 4-1) = 80 people. Number of entrants.

80 40% = 200 people. The number of students in the school.

12 (2 5 + 3 4-1) = 80 people. Number of entrants.

80 40% = 200 people. The number of students in the school.

The question is, what do you ask? I didn't explain it clearly!

Set the number of participants x people, according to the meaning of the question:

2 5 x + 3 4 x) -1 = 12 to get x = 80

So the number of sixth graders is:

80 40% = 200 people.

[Analysis].

According to one of the principles of repulsion: the sum of the number of elements of class A and class B = the number of elements belonging to class A + the number of elements belonging to class B - the number of elements that are both class A and class B, listing the equivalent relationship is the key to completing this problem;

This problem can be solved by the equation, if the total number of participants in the competition is x, then there are (3 5) x people who participate in the language competition, (3 4) x people who participate in the mathematics competition, and 14 people who participate in both categories, according to the principle of repulsion, the equation can be obtained: (3 5) x + (3 4) x-14 = x, after solving the equation to find the total number of participants in the competition, you can find the total number of people in the whole grade.

Answer: The total number of participants in the competition is x.

There are (3 5) x people participating in the language competition.

There are (3 4) x people participating in the mathematics competition.

The equation is derived from the question:

3/5)x+(3/4)x-14=x

12x+15x-280=20x

7x=280

x=40 (person).

How many people are there in the whole grade?

100 (person).

A: There are 100 students in the whole grade.

Let the total number of people be x

then participate in the competition for.

Participating languages are:

Participate in mathematics has.

Since there are 12 students participating in Chinese mathematics at the same time, the number of Chinese students plus the number of mathematics repeats the equation of 12 people: the solution is x=200

If there are scores in the question, they should be expressed by fractions, which is better calculated. Here's the answer:

Solution: There are a total of x people in the sixth grade.

There are 40 100 people who participate in the competition, which is 2 5x people. Then the number of people who only participate in the language competition is (2 5 2 5x-12), and the number of people who only participate in the mathematics competition is (3 4 2 5x-12). List the equations:

2 5 2 5x-12) + (3 4 2 5x-12) = 2 5x solution x = 400 people.

That is, there are 400 students in the sixth grade. (You can substitute it into the calculation to further obtain the specific number of people participating in the language and mathematics competitions.) ）

Suppose there are x people who participate in the math competition, three-quarters of the people who participate in the math competition, x two-fifths of the people who participate in the language, then three-quarters plus two-fifths and subtract one is the proportion of the number of people who participate in both language and mathematics -- that is, three-tenths of the twentieth 12 divided by it gives 80, so in the sixth grade, there are 80 divided by 40 percent and 200 people are obtained.

Let the number of participants be x, x*2 5+x*3 4-12=xx=80

The total number of people is 80 40% = 200 people.

From the meaning of the title, it can be seen that only those who participate in language competitions account for all: 1-2 3=1 3, and those who only participate in mathematics competitions account for all

1-3 4=1 4, the number of participants in both subjects accounts for all: 1-1 3-1 4=5 12, and the total number is: 45 divided by 5 12=108, so the number of people who only participate in the mathematics competition and do not participate in the language competition is:

108*1 4=27 (person).

A: The total number of participants in the contest is x:

Then how many people participated in the mathematics competition but did not participate in the language competition: 2x 3-45;

How many people participated in the language competition but did not participate in the mathematics competition: 3x 4-45;

2x 3-45) +3x 4-45) +45=x108 of the solution

So: how many people participated in the mathematics competition but did not participate in the language competition: 2x 3-45 = 27

Solution: Two-fifths of the total number of participants in the language competition and three-quarters of the total number of students in the mathematics competition, so both of them participated. Therefore, the extra part of the sum of the two is the one that participates in both of them once, so the one who participates in both accounts for 2 5 + 3 4-1 = 3 20 of the total number of people in the competition

Since there are 12 participants in both, the total number of participants is 12 (3 20) = 80 because the number of participants is 40% of the total number of students in the grade, so the number of participants in the whole grade is 80 40% = 200.

There are 200 students in the whole grade.