Elementary school math problems, very simple, if it s good, it must be added, I speak very arithmeti

It took Xiao Ming 4 minutes to walk from Xinhua Road to Jiefang Road, Xiao Fang took minutes, and the speed ratio of Xiao Ming and Xiao Fang was: 5:4

In order to use 1 3, 1 12, 1 and 7 9 and x to form the ratio, then x is (4 9) A, B, C, and Shan people do the same job, their work-efficiency ratio is: A: B 3:2, B: C 3:4, and the highest work-efficiency ratio among the three is (A).

It is known that 3 8m 9n, then m and n are (positive) proportional.

The speed ratio between Xiao Ming and Xiao Fang is 4:5

In order to use 1 3, 1 12, 1 and 7 9 and x to form the ratio, then x is (4 9) A, B, C, and Shan people do the same job, their work-efficiency ratio is: A: B 3:2, B: C 3:4, and the highest work-efficiency ratio among the three is (A).

Note: At the same time, the proportion is enlarged; A:B:C 9:6:8 3 8m 9n, then m and n are in ( anti ) ratio.

1.The speed ratio of Xiao Ming and Xiao Fang is 4:5

It was 16 out of 27

3.The highest ergonomic efficiency of the three is A.

4.then m and n are (positively) proportional.

Give me extra points!

The speed ratio of Xiao Ming and Xiao Fang is 4:5.

Time is multiplied by 5 and then divided by 4 to get a time ratio of 5:4, because distance = time speed, so the walking speed ratio is 4:5.

x=36, using 3 denominators to calculate the least common multiple.

Based on B, the ratio of the three is A: B: C = 9:6:8, so the highest work-efficiency ratio among the three is (A).

I use two methods for the last question:

1. See directly. There are no negative numbers.

2. Calculate the ratio of m n. m/n=24/1

So m and n are (positively) proportional.

Question 1: The ratio of speed is the opposite of the ratio of time, so it is 4:5 Question 2: 36

Question 3: A.

Question 4: Proportionality.

The total number of gears turned is the same.

Therefore, the number of propylene teeth in the first question is (7*42) 6=49.

The second reason is the same as above, so the number of turns is 7*8=56 turns.

1) The length is 18 cm, the width is 2 cm

Circumference: (18+2) 2

40 (cm).

Area: 18 2 = 36 (square centimeters).

2) 12 cm long, 3 cm wide

Zhou carries the difficulty: (12+3) 2

30 (cm).

Area: 12 3 = 36 (square centimeters).

3) Length 6 cm, width 6 cm

Circumference: 6 4 = 24 (cm).

Area: 6 6 = 36 (square centimeters).

4) Length 9 cm, width 4 cm

Circumference: (9+4) 2

26 (cm).

Area: 4 9 = 36 (square centimeters).

Square of (2b) = 4 (c+a)(c-a).

4b^2=4c^2-4a^2

a^2+b^2=c^2

c is a right angle. 5a-3c=0

a:c=3:5

Let a=3x and c=5x

b = root number (c 2 - a 2) = 4x

sina + sinb + sinc = 3 5 + 4 5 + 1 = let a = 2xc = 3x

Angle c = 90 degrees.

b by the Pythagorean theorem = root number 5 times x

sinb = (root number 5) 3

1.Cylindrical volume = cubic decimeter.

Base area = square decimeters.

2.With the right-angled side of 4 decimeters as the axis, v cone = 3 * 3 * cubic decimeters.

1, cubic decimeter).

square decimeter) 2, the first kind.

r = 3 dm, h = 4 dm.

1 cubic meter).

The second type is r = 4 dm, h = 3 dm.

1 cubic meter).

1。Let the ground area be s

sh-1/3sh=

Bring in h = 3 to get s = square decimeter).

cubic decimeters).

1.etc = is the volume of the cone).

Multiply by 3 3 = 2It's easy!

Let's draw a diagram first, you can know that the cone is 4cm high and the bottom radius is 3cm.

Multiply (3 times 3) multiply 4 times one-third.

12 times (=.)

1. Square decimeters.

2*sq dm.

Let's give you the second question first, the volume formula: the square of the radius * the height divided by 3. It is 3 * 3 * decimeters to the 3rd power).

1.The base area is decimeter2

2.The volume is decimeter3

taijiandan is too simple, I'm embarrassed to say.

Question 1—x 5 7=, 14 (

Question 2—56 4 = 14 (square centimeters) 14 2 = 7 (centimeters) 7 7 (7-2) = 245 (cubic centimeters).

Question 3 - The ratio of the circumference of the bottom surface is 2:3, so the radius is also 2:3, so the ratio of the bottom area is 4:9

5 4:6 9=5:8 The answer is a

Question 4 - From the center of the circle to any point on the circle, this is the distance between the points and the points, so it is called a line segment.

The answer is b!!

Answer to question 1: 35

Answer to question 2: 245

Answer to question 3: a

Answer to question 4: b

25 of (240) km is 60 km, (48) km is 60 km after 25 increases, (80) km is 60 km after 25 minus 25?

Pear trees = 60 4 5 = 48 trees.

60 (1+1 4)=48 trees.

60 (1-2, 5)=100 This is the number of hens 100-60=40 is for cocks.

You can let the unary equation x-2x 5 =60 for x hens, and we can calculate x=100

25 of (240) km is 60 km, (48) km is 60 km after 25 increases, (80) km is 60 km after 25 minus 25?

1: There are 60 peach trees in the orchard, which is 5/4 of the pear trees, how many pear trees are there?

60 5 4 48 (tree).

2: There are 60 peach trees in the orchard, 1/4 more than pear trees, how many pear trees are there?

60 (1 1/4) 48 (trees).

Aunt Liu's number of roosters is two-fifths of that of hens, and there are 60 more roosters than hens. How many roosters and hens does Aunt Liu have?

There are 60 (1 2/5) 100 hens

Roosters have 100 2/5 40 (only).

Master Li's scientific and technological invention won 4,000 yuan. According to the regulations, the part exceeding 800 yuan shall pay 14% of the personal income tax. How much is Master Li's take-home bonus?

A city has built a section of elevated road, which has been repaired for 85 years, and there are still kilometers left to be repaired. How many kilometers is this elevated highway long.

A city has built a section of elevated road, and has built a total length of 85, which is exactly one kilometer. How many kilometers are left to be repaired?

After the price of a commodity is reduced by 15, it is 340 yuan, how much is the original price of this commodity?

Connect the conditions with the corresponding formulas.

There are 60 soccer balls in the school, how many volleyballs are there in the school?

There are x volleyballs in the school.

1) 20 60 + 60 20 more than volleyball

2) 20 60-60 20 less than volleyball

3) The number of volleyballs is 20 x x 20 = 60 more than football

4) The number of volleyballs is 20 x + x 20 = 60 less than that of football

1)x-x×20％=60

2)x+x×20％=60

Fill in the blank: 25 km of (240) km is 60 km, (48) km is 60 km after 25 is added, (80) km is 60 km after 25 is decreased?

240 km, 48 km, 80 km.

60 divided by 5/4 equals 48. There are 48 pear trees.

60 (1+1/4) equals 48 trees. There are 48 pear trees with x hens and 2x fifths of the roosters

Did you make a mistake in writing this question? Is it that there are 60 fewer roosters than hens?

x - 2/5 x = 60

Find x=100

100 hens, 2/5 of the roosters x = 40.

48 km.

75 km. 1 pear tree = 60 4 5 = 48 trees 60 (1 + 1 4) = 48 trees.

60 (1-2, 5)=100 This is the number of hens 100-60=40 is for cocks.

You can let the unary equation x-2x 5 =60 for x hens, and we can calculate x=100