6th Grade Math Problems! I m going to write it right now, big brother and sister, come and help

When all of the water is put into the water, the water in the bucket rises by 9cm, and the volume of the rising part of the water is the volume of the steel bar.

If the steel bar in the water is exposed to the water surface by 8cm, then the water in the bucket will drop by 4cm, and the volume of the falling part of the water is the volume of the steel bar 8cm long above the water surface.

The bottom area of the bucket: square centimeters).

The volume of the steel bar: 157*9=1413 (cubic centimeters).

Solution: The volume occupied by 8cm steel bar = 5 2 8 = 200 (cm 3) The bottom area of the bucket is fixed, and the ratio of volume is equal to the ratio of height.

Let the volume of the steel bar be x(cm 3).

4：9=200π：x

Find: x=450 (cm3).

Let the length of the cylindrical steel bar be L, and the bottom area of the circular water storage tank is S.

l : l-8) = 9s : 9-4)s = 9s : 5s = 9:5

l = 18 cm

Volume of steel bar: l * r = 18 * 25 = 1413 cubic centimeters.

t is the volume, s is the surface area of the circle of the cylinder h is the height.

s= t=s*h t1=s*(h-8)

Set the surface area of the bucket mouth to be s1

t=s1*9 t1=s1*5

s*h=s1*9 s*(h-8)=s1*5 can be simplified to obtain t=sh=cubic centimeters.

= 1413 (cubic centimeters).

Choose me! I'm on your knees!

5×5×π×9=225π（cm³）

A: The volume of steel bars is cubic centimeters.

Let the volume of the steel bar be v, v (v- 5 5 8) = 9 5

So v = 450 = 1413 (cubic centimeters).

Solution: Suppose the alcohol containing 15% water is X grams.

raid (1 15%) x bai(1 5%) du500 x) zhi500

88%85%x+95% (500 x) 88% 50085%x+95% 500 95% x 44010% x 95% 500 440 The 5% alcohol content of the aqueous dao is:

10% x 475 440 500 350 150 (grams) x 35 10%.

x 350 (grams).

Set the number of alcohol with 15% water.

The amount of x is set to be the amount of alcohol with 5% water content as y

Alcohol with 15% water is the alcohol concentration.

85% of the alcohol, 5% of the water is the alcohol concentration of 95% x + y = 500

85%x+95%y=88%*500

Solving the above equation yields x=350 y=150

The amount of alcohol with 15% water is 350 grams The amount of alcohol with 5% water is 150 grams.

Suppose 15% x gram and 5% y gram.

Column equation: x+y=500

1-15%)*x+(1-5%)*y=88%*500 to solve the equation.

Suppose one has x grams, and the second has 500-x grams.

1-15%）x+（1-5%）(500-x)=500*88%x=350

So 15% of 350 grams 5% of 500-350 = 150 grams.

Solution: Let the 15% alcohol content of water be x, then the 5% alcohol content of water is (500-x).

15%x+5%(500-x)=(1-88%)*500

x=350

350 grams with 15% water and 150 grams with 5% water.

1 Let the armor be x m 9 10x=18 x=20

2 1x40=40 2x20=40 5x8=40 8x5=40 4x10=40 The minimum is scheme 3 and 4 circumference 26

3 Let there be x days on sunny days, then the equation for rainy days (8-x) days is 20x+12(8-x)=8x1420x+96-12x=1128x = 16

x=2, so sunny days: 2 days, rainy days: 6 days.

4 500 25+1 = 21 Why +1 Let me give you an example, if you have three trees together, it will be 50 meters, so in the end, it will be +1

5 Because of the elimination system, 64-1=63 games.

1. (1-1 10) A = 18

9 10 A = 18

9A = 18*10

A = 202, find the factor of 40: 1 and 40 2 and 20 4 and 10 5 and 8 The minimum circumference of the rectangle is (5+8)*2=26

3. The total number of pine nuts: 8 * 14 = 112 Set: There are x days on sunny days, and 8-x days on rainy days.

20x+12*(8-x)=112 Solution x=2 So if there are 2 sunny days, then 6 rainy days.

The minimum circumference of the rice species is 26 sunny days and 6 rainy days.

1: 56 7=8 (days).

10*8-56) (10-6)=6 (days) There are 6 rainy days2: (208-64) 2=72(min) Fraction of the circle 72+64=136 (min) The fraction of the square.

10*20-72) (20+12)=4 Number of questions that Yuanyuan got wrong10-4=6 Number of questions that Yuanyuan got right.

10*20-136) (20+12) = the number of questions that are done incorrectly in 2 squares, and 10-2 = the number of questions that are done correctly in 8 squares.

3: (220+200) (4+2)=70 (4*70-220) (4-2)=30 (chickens) Number of chickens 70-30=40 (birds) Number of rabbits.

A: Six of these days were rainy.

points, each of which does 10 questions, all correspond to 400 points.

Fang Fang score: 64 + (208-64) 2 = 136 points, (Fang Fang is 64 points more than Yuanyuan).

200-136) (20+12) = 2 lanes. 10-2 = 8 round scores: (208-64) 2=72 points, (200-72) (20+12)=4

Dao, 10-4=6Dao.

Answer: Fang Fang does 8 things right, and Yuan Yuan does 6 things right.

3.Set up x chickens and rabbits.

x2+4y=220

4x+2y=200

Solve the equation x=30, y=40

A: There are 30 chickens and 40 rabbits.

1.If you've ever studied equations, you should be able to do it in a few clicks.

2.If you haven't learned the equation yet, you can try the difference method.

For example, in the first question, it is obvious that 56 divided by 7 = 8 days. Assuming that all rainy days are made, then 8*6=48 times. 56-48=8；

But every sunny day is 4 more times than a rainy day. Then on a sunny day, 8 divided by 4 = 2 times. So the rainy day is 6 times.

I'll give an answer to the last two questions, and the method is pretty much the same.

Answer: 1: 6

Therefore, it has been transported for a total of 8 days, and if there are x days for rainy days, then there are 8-x days for sunny days6*x+10*(8-x)=56

Solutionable x 6

2.If Yuanyuan does the right x, then he does the wrong 10-x.

The score is 20*x-12*(10-x).

If the square is 64 points more than the circle, then the square score is 20*x-12*(10-x)+64, and the above equation is added to 208

x=6 can be obtained, so the circle is 6 right, and the square is 8 right.

3.Set up x chickens and rabbits.

2x+4y=220 (1)

4x+2y=200 (2)

Multiply (1) by 2 to give 4x+8y=440 (3) (3)-(2) to get y=40 x=30

Question 1: There are a total of x rainy days. Equations are listed according to the question.

8-x)*10+6x=56

4x=-24

x=6 A: There were 6 rainy days in these days. Question 2.

Solution: If there are x rainy days, then there will be (56 7-x) sunny days.

6x+10(56/7-x)=56

6x+80-10x=56

4x=24x=6A: There are 6 rainy days.

The seller intends to reduce the price: 100 5% 5 yuan.

Principal multi-order: 5 4 20 sets.

After the price reduction, the profit of the 80 sets of desks ordered before was reduced: 80 5 400 yuan After the price reduction, the profit of each of the 20 sets of desks newly ordered was: (400 + 100) 20 25 yuan.

The cost price of each set of desks is: 100 5 25 70 yuan.

Solution: Design: The cost of each set of this kind of desk is X yuan.

80（100-x)+100=(80+4x5)(95-x)8000-80x+100=9500-100x20x=1400x

x=70A: The cost of each set of this kind of desk is 70 yuan.

Set the original with 6x and 5x yuan each.

6x-25：5x-25=7：5

7*(5x-25)=5*(6x-25)

35x-175=30x-125

5x=50x=10

It turns out that Xiaogang = 10 * 6 = 60 yuan.

Solution: Let's assume that the original brought 6x and 5x yuan each.

6x-25：5x-25=7：5

7*(5x-25)=5*(6x-25)

35x-175=30x-125

5x=50x=10

10 6 = 60 yuan.

Solution: If Xiaogang brought 6x yuan, then Xiaojing brought 5x yuan.

6x-25:5x-25=7:5

7（5x-25）=5（6x-25）

35x-175=30x-125

5x=50x=10

When x=10.

Xiaogang: 6x=6 10=60

Xiaojing: (5x=5 10=50) This can be left without writing Answer: Xiaogang brought 60 yuan.

Let Xiaogang bring x yuan, then Xiaojing brings 5 6 * x yuan, and there is (x-25):(5 6*x-25)=7:5(x-25)*5=(5 6*x-25)*7 solution: x=60

That is, Xiaogang brought 60 yuan.

Answer: Set Xiaogang brought x yuan, and Xiaojing brought y yuan.

Then: x y=6:5

x-25)/(y-25)=7:5

The two equations yield: x=60 y=50

Xiao Gang brought 60 yuan.

Solution: If A has a deposit of x yuan, then B has a deposit of 5 4x yuan. According to the title, x+40=5 4x-40

1/4x=80

x=3205/4x=400

So A has $320 and B has $400.

Let the total deposit be $x, then A has (4 9) x yuan, and B has (5 9) x yuan (4 9) x + 40 = (5 9) x-40

1/9)x=80

x=720 yuan.

Then A has 720 * 4 9 = 320 yuan, and B has 720 * 5 9 = 400 yuan.

RMB.

1, Star Elementary School has 100 students in the first grade, 1 more than the second grade 1 4, how many are in the second grade?

100 (1 1 4) 80 (person).

2. Uncle Wang deposited 5,000 yuan in the bank for two years, the annual interest rate is, how much yuan can Uncle Wang get interest when it expires (without paying interest tax)?

5000 yuan).

3, abc is a natural number that is not 0, 3 4a = 2 5b = c, then the largest number of abc three numbers is (b).

Order 3 4a 2 5b c 1

then a 4 3, b 5 2, c 1

So the maximum number is b

4. Solve the equation, 2 3x+50%x=42

Solution: (2 3 50%) x 42

x＝42÷7/6

x 36 I wish you progress in your studies.

(1+1 4) = 80 people.

2. Yuan 3 and abc are natural numbers that are not 0, 3 4a=2 5b=c, then the largest number of abc three numbers is (b).

3x+50%x=42

Solution 7 6x=42

x=42÷7/6

x=36If you don't understand something, please ask a question.

1. Number of second-year students *

3. Because 3 4a=2 5b=c, a>3 4a, then we know a>c and a=8 15b, we can know b>a, so the three numbers b are the largest, that is, b>a>c

4. 2 3x+50%x=42 i.e. 7 6x=42 so x=42*6 7=36

2.If the principal is transferred: 5000*RMB.

If the principal and interest are transferred: 5000*

3.The process will be solved for you if you need answer b

4. 2/3x+1/2x=42

4/6x+3/6x=42

7/6x=42

x=36 for my sister.

1 means that 5 to 4 times the second grade is 100, and the second grade is 80.

23 a=4 3c b=5 2c The comparison found that b was the largest.

1 Divide 100 into four parts, each part is 25 people, then there are 75 people in the second grade, 2 5000 multiplied by 2 and multiplied by the answer.

3 There is a problem with this question, and frankly it is a wrong question! Whether abc is a continuous or discontinuous natural number, you didn't make it clear!

4 solution: 2 3x+50%x=42

2/3x+1/2x=42

2/3+1/2)x=42

7/6x=42

x=42*6/7

x=36