1 6 3 9 5 12 what do you want to fill in the following two blanks? Why ask for help

1 6 3 9 5 12 what do you want to fill in the following two blanks? Why ask for help

1 6 3 9 5 12 （7 ） （15）
The odd number is 1 3 5 7
The even number is 6 9 12 15

One fourth of a number is 20. What is one fifth of a number

Let this number be x, then x / 4 = 20, so x = 80, 80 / 5 = 16

Find the rules, fill in the numbers and say the reasons
There is a field form
0 3 ---- 3 2 ---- 2 3
3 9 ---- 3 15 ---- 2 x
1 2 ---- 4 5 ---- 7 8
3 7 ---- 6 34 ---- 9 x
How much is the number of X

1) 3 the first line has three 3 2) 1 1 -- 4-7 2-5-8 3-6-9 7 -- 4-1

Fill in the numbers regularly (please explain the reason)
1、4、9、14___ 37、60

23.1+4=5 9+5=14 14+9=23 23+14=37 37+23=60