A difficult 6th grade math problem ratio .

Set the ratio x then male 5x female 4x male in the second semester if a male transfers out in the second semester then male 5x-1 female or 4x [5x-1] 4x=6 5 so as to find the value of x then male is equal to 5x-1 female is equal to 4x Thank you, I hope I hope I can help you!

Last semester, the ratio of boys to girls was 5:4, which is 25:20, and this semester: 6:5, which is 24:20

The girls remain the same, the boys are 1 less, and the result is 1 less, so 1 represents 1 person.

There are 24 * 1 = 24 boys and 20 girls

A total of 44 people.

Woman. 1*(24 20) 44 people.

Grasp the characteristics of the number of girls in the question, the two ratios of the boys before and after, into a ratio, the difference between the boys before and after the ratio is 1, this 1 is the corresponding amount of the boy in the text to transfer out of one of the 1 people, 1 1, find the value of 1 in the ratio, now there are such 1 in the class (20 44), multiply it to find the answer.

Can you use a system of equations, if you can, that's it.

Let the boy be x and the girl y

x/y=5:4

x-1)/y=6:5

y=20x=25

If you can't use it, take a look below.

It's the ratio after you transfer out a person.

Let's say that the boys are 5k and the girls are 4k.

5k-1）/（4k）=6/5

k=5 The current number of students is: 5k-1+4k=9k-1=44.

1.If you sell 300 pieces of red paper and 400 pieces of white paper every day, a few days later, all the red paper is sold out and there are 1400 pieces of white paper left, how many pieces of white paper are in stock?

Solution: Set x blank paper in stock, then red paper x 2.

The number of days to sell out of red paper is (x 2) 300=x 600

When the red paper is sold, the number of pages bought on the white paper is 400*x600=2x3.

So according to the title.

x-2x/3=1400

x/3=1400

x=4200

That is, 4,200 sheets of white paper in stock.

2.Twenty years ago, Dad was 6 times older than Xiaoling, and today, Dad is 2 times older than Xiaoling. Ask for Xiaoling's age this year.

Solution: If Xiaoling's age this year is x, then Xiaoling's age 20 years ago was x-20 years old, so Dad's age 20 years ago was 6 (x-20), according to the title.

6(x-20)+20=2x

6x-120+20=2x

4x=100

x=25, that is, Xiaoling's age this year is 25 years old.

3.The ratio of the number of young pioneers of team A and team B is 7:3, if 30 people are transferred from team A to team B, the ratio of defeat to team A and team B is 3:2, ask team B how many people are there?

Solution, if team B has x people, then team A has 7x 3 people, according to the question.

7x/3-30)/(x+30)=3/2

14x/3-60=3x+90

5x/3=150

x=90, i.e. the original number of team B is 90.

4.A and B are 340 kilometers apart. A and B two passenger cars respectively from the two places at the same time opposite each other, after 4 hours, A and B two cars meet, it is known that the speed of A and B is 8:9, ask what is the speed of B car?

Solution: Let the speed of car B be x, then the speed of car A is 8x 9, according to the question.

4*(x+8x/9)=340

4*17x/9=340

x = 45, i.e. car b is traveling at a speed of 45 km/h.

Problem: The problem of taking soybeans.

162 soybeans, two people take turns to take soybeans.

Rules: Each person takes at least 1 soybean at a time, and a maximum of 3 seeds until the soybean is finished, and whoever gets the last soybean wins.

Working in pairs and a few times, can you find a way to win?

Choose 2 pieces, and then take the sum of the other person's numbers to 4 each time to win.

Namely. Take 2 first, then take 1 from others, and take 3 for yourself

Because 162 = 4 * 40 + 2

So keep the last 4 capsules and take them yourself.