There are () fractions that satisfy the following conditions at the same time: 1, greater than one sixth, less than one fifth; 2, both numerator and denominator are prime numbers; 3, denominator is two digits

There are () fractions that satisfy the following conditions at the same time: 1, greater than one sixth, less than one fifth; 2, both numerator and denominator are prime numbers; 3, denominator is two digits

There are (12) scores satisfying the following conditions at the same time
2/11
3/17
5/29
7/37
11/59
11/61
13/67
13/71
13/73
17/89
17/91
17/97

All fractions that satisfy the following conditions at the same time: greater than one sixth and less than one fifth: both numerator and denominator are prime numbers; fraction

There are countless
2/11
3/17
5/29
7/37,7/41
11/59,11/61
13/67,13/71,13/73
17/89,17/97,17/101
19/97,19/101,19/103,19/107,19/109
.

Please write all the fractions with the following conditions: ① greater than 1 / 6 and less than 1 / 5. ② the numerator is a one digit prime number. ③ the denominator is a two digit prime number

Because 1 / 6 ≈ 0.166667, 1 / 5 = 0.2
7/37≈0.1891891892
Therefore, the qualified can be: 7 / 37

Write a fraction which is greater than 1 / 15 and less than 1 / 14 and whose numerator and denominator are prime numbers: ()

2/29
3/43
5/71
5/73
Simultaneous amplification of numerator and denominator
And then it's settled
2/30 2/29 2/ 28
3/45 3/43 3/42
5/75 5/73 5/71 5/70
It's important to know the method

Fill in brackets in the following equation to make the equation hold 1 + 2 * 3 + 4 * 5 + 6 * 7 + 8 * 9 = 1717
By the way, can you tell me about the problem-solving skills of this kind of problems?

1+2×3+[(4×5+6)×7+8]×9=1717

1 / 3 + 1 / () + 1 / () + 1 / () + 1 / () + 1 / () + 1 / () + 1 / () + 1 / 24 = 1. Fill in the brackets with different integers from 4 to 23 to make the equation hold
How to understand
What's your idea

1/3+1/(9 )+1/(18 )+1/(10 )+1/(15 )+1/(6 )+1/(8 )+1/24=1
thinking
1/(9 )+1/(18 )=1/6
1/(10 )+1/(15 )=1/6
1/(6 )+1/(8 )+1/24=1/3

1 / 3 + 1 / () + 1 / () + 1 / () + (1 / () + 1 / () + 1 / () + 1 / () plus 1 / 24 equals 1. Fill in the brackets with different integers from 4 to 23

1 / 3 + 1 / (6) + 1 / (9) + 1 / (12) + (1 / (15) + 1 / (18) + 1 / (21) plus 1 / 24 equals 1

3.4.6.8.23.25.27.28. Fill in a bracket below to make the equation hold () + () = () + () = () + () = () + ()

Use the minimum plus the maximum, all equal to 31
（3）+（28）=（4）+（27）=（6）+（25）=（8）+（23）

"Please fill in the brackets with different integers from 4 to 23 (see the supplement for details)
"Please fill in the brackets with different integers from 4 to 23 to make the following equation true:
1 = 1 / 3 + 1 / () + 1 / () + 1 / () + 1 / () + 1 / () + 1 / () + 1 / () + 1 / () + 1 / 24 "

1=1/3+1/（4）+1/（6）+1/（8）+1/（9）+1/（12）+1/（18）+1/24
Because: 1-1 / 3-1 / 24 = 1-8 / 24-1 / 24 = 15 / 24 = 5 / 8
1/18+1/9=1/18+2/18=1/6
1/12+1/6=1/4=2/8
1/4+1/8=3/8
Try to use: 1 / x + 2 / x = 3 / x, where x is a multiple of 3

1 / 13 = () 1 / 13 + () 1 / 13; 1 / 23 = () 1 / 13 + () (fill in different integers in brackets)

The answer is not unique. As long as the product of two spaces is 13 times / 23 times of the sum, one of the answers is: 1 / 13 = 1 / 14 + 1 / 182
1/23=1/24+1/552