Primary school math questions, about fractions, elementary school math fraction calculation question

52/39 is the simplest fraction: the numerator and denominator are divided by 13 to get 4/3;

The sum of the numerator and denominator of a fraction is 28, and after about two fifths, it is worth two-fifths

Numerator = 28 (5+2) multiplied by 2 = 8

Denominator = 28 (5+2) multiplied by 5 = 20

This score is 8 20

52/39

39 divided by 13) (52 divided by 13) = 4/3 of the numerator, then 2x + 5x = 28

x = 4 molecule is 2x = 8

The denominator is 5x=20

1) The greatest common factor of 39 and 52 is 13, so 39 13 52 13 = 3 4

2) The sum of the numerator and denominator of the fraction after reduction is several times smaller than the sum of the original numerator and denominator, which means that the fraction is divided by a few, because the multiple of the reduction is the same.

5 + 2 = 7, 28 7 = 4, indicating that 4 is used to divide the part. So the original fraction is 2x4 5x4=8 20

Fifty-two thirty-nineths, the numerator and denominator are divided by 13 = 428/3 times 5/7 = 20

28 times 2/7 = 8

A: This number is 5/4

1) The numerator and denominator are divided by 13 at the same time

2) Let 5x be the original denominator and 2x be the original numerator, then 7x=28 and x=4 then the original fraction is 8/20

Question 1: 39 52 divide by 13 to get 4 3

Second question: Because the fraction is about two-fifths, the numerator is equal to 5:2 with a denominator equal to 5:2, and the numerator is 5x and the denominator is 2x

So 5x+2x=7x=28

x=4, so this fraction is (4x5) (4x2)=20 8

Divide the numerator and denominator by 13 at the same time to get 4/3 28 (5+2)=4 4*2=8 4*5=20 8 20

52 39 = 52 divided by 13 39 divided by 13 equals 4 3 It is not good to divide by this symbol, which is represented by Chinese characters, that is, 39 and 52 are divided by 13 at the same time Ideas: Add 7 boxes, divide the boxes into 5 and 2, there are 28 apples in these 7 boxes, and the fruits in each box are the same, then there are 4 fruits in each box, similar to this question, these two numbers are 20 and 8That is, this fraction is 2 5 If this question is to find out what this number is, then write 2 5 directly You can write a fraction with the numerator and denominator multiplied or divided by a non-zero number at the same time, and this number does not change.

9/5 5/7 = 9/7

16 5/8 = 128/5

5/8 4/15 = 75/32

7/16 5/12 = 35/192

7/27 3/10 = 70/81

40 5/8 = 64

160 4/5 = 200

1-1/5 4=19/20

1/6 (2/3 + 3/4) = 2/216/17 - 5/8 = -5/16

4/7 2/3 = 12/14

14/25 1/2 = 28/25

4 11/20 = 44/20

4/5 1/8 = 32/5

8/25 2/5 = 4/5

6/7 2/3 = 12/21

150 18/25 = 625/3

6/7 4/3 = 8/7

8/5 5/6 = 4/3

7/9 3/14 = 1/6

3/7 8/15 = 8/35

2/9 3/2 = 1/3

5/9 2/5 = 2/9

3/5 11/15 = 33/75

5/8 8/15 = 1/3

17/20 5/8 = 17/32

18 300 out of 15 = 360

15/8 5 = 3/8

25 2/3 = 75/2

16 8/5 = 10

42 21/8 = 16

15/14 5/7 = 1/2

4 11/20 = 80/11

1/2 14/25 = 25/28

4/5 5/4 = 16/25

3/4 3/5 = 5/4

24/15 32/35 = 7/4

The number of people who won the third prize accounted for 1-3 4 = 1 4

The number of people who won the first prize accounted for 1-2 3 = 1 3

The second prize winner accounts for 1-1 4-1 3=12 12-3 12-4 12=5 12

There are x people who won the first prize, Y people who won the second prize, and Z people who won the third prize.

x+y=3/4

y+z=2/3

x+y+z=1

Finding the three values y is the answer. (Ask for it yourself).

Solution: A: 140x3 (3+4) = 600,000 pieces.

B: 140-60 = 800,000 pieces.

A: A produces 600,000 pieces, B produces 800,000 pieces.

Analysis process: A 4 times is equal to B 3 times, so A is 3 4 of B, that is, A accounts for 3 (3+4) of the total, that is, 3 7

If you still don't understand, please continue to ask.

Let the number of production of A be x and the number of production of B be y, then:

4x=3y x+y=140=> x+4/3x=140

x=60 y=80, so Party A produces 600,000 pieces, and Party B produces 800,000 pieces.

1.The number of students in Class A is 25% higher than that in Class B, and the number of students in Class B is how many percent less than the number of students in Class A?

Solution: 25% (1+25%)==

A: The number of students in Class B is 20% less than that in Class A

2.A plant had planned to burn 240 tons of coal per month. Actual monthly savings. How many tons of coal are actually burned per month?

Solution: 240 (.)

210 (tons).

A: The actual monthly coal burning is 210 tons.

3.A car can cover the entire distance in 3 hours. Ask for the percentage of the car that has traveled the whole distance after 3/5 of an hour.

Solution 3 5 3

A: 20% of the whole journey.

The unknown number B is before the word, using division) ==

Unknown numbers are after the ratio, and known numbers are multiplied before the ratio).

210 (tons).3.Three-fifths to three=one-fifth (the previous number is compared to the next) one-fifth = 20%.

Backwards: 24 (1-1 4) = 32 (m).

32 (1-3 8) = m).

Solution: Let this rope be x meters long.

1-3/8)x(1-1/4)=24

5/8x3/4=24

15/32x=24x=

1.This rope turned out to be 24 (1-3 8-1 4) = 64 m2Let this rope be x meters long.

x-3/8x-1/4x=24

3/8x=24

x=64 The rope turned out to be 64 meters long.

Solution: 4-1=3 24 3=8 (m) 8*4=32 (m).

8-3 = 5 32 5 = m) m).

Answer: This rope was originally a meter long.

Set the total number of tasks to 1

A can complete 1 out of 10 tasks per day

A and B cooperate to complete 1 of 6 tasks per day

So B completes 1 6-1 10 = 1 15 per day, so B needs 15 days to complete the task.

It will take days to complete half of the way.

The work efficiency of A and B cooperation is: 1 6

The efficiency of A alone is: 1 10

B's work efficiency alone is: 1 6-1 10=1 15 B's time to complete half of the workload is: 1 2 1 15 = days.

A can complete 1 out of 10 tasks per day

A and B cooperate to complete 1 of 6 tasks per day

So B completes 1 6-1 10 = 1 15 per day, so B needs 15 days to complete the task.

It will take days to complete half of the way.