Find out the following rules: 1,5,4,8,7,11,10, () what number to fill in the blank? Find out the following rules: 1,5,4,8,7,11,10, () What's the number in the blank, please?

Find out the following rules: 1,5,4,8,7,11,10, () what number to fill in the blank? Find out the following rules: 1,5,4,8,7,11,10, () What's the number in the blank, please?

1+4=5
5-1=4
4+4=8
8-1=7
7+4=11
11-1=10
10+4=14
…………
The rule is to add 4 and subtract 1

Numerical reasoning: what are the two terms of 7,5,3,10,1, (), () spaces?
（1）15,4 （2）20,-2 （3）15,-1 （4）20,0

The answer is 20,0
Grouping: group 1, 3, 5, 7, group 2, 4, 6
1. Group 3,5,7: 7,3,1,
The results show that: 7 = 3 × 2 + 1; 3 = 1 × 2 + 1, 1 =? × 2 + 1, = 0
2. Group 4 and group 6: 5, 10?
= 20

Numerical reasoning 7.7.8.10 (13). 17.22 why do you fill in 13 in brackets

7-7=0
8-7=1
10-8=2
13-10=3
17-13=4
22-17=5
If two adjacent items want to be subtracted, they will be equal difference sequence, and the tolerance is 1

There are 100 chickens and ducks in Xiaoming's family. They bought 1 / 20 chickens, 17 more than ducks. How many chickens and ducks did Xiaoming's family have?

Suppose there are x chickens and Y ducks
X+Y=100
X-1/20X-17=Y
X=60
Y=40

There are 36 chickens in Xiaohong's family. The number of ducks is 4 times that of chickens. The number of geese is 9 times that of ducks. How many geese in Xiaohong's family?

The number of ducks is 4 times that of chickens and 9 times that of geese
Is the number of ducks four times that of chickens and nine times that of geese
If it is
The calculation is as follows:
36 × 4 × 9 = 1296

Mother Li had 100 chickens and ducks. Later, she sold 1 / 5 of the chickens and bought back 8 ducks. At this time, the chickens and ducks were equal. How many chickens and ducks were there?

Suppose that there are x and Y chickens and ducks
x+y=100
x-x/5=y+8
The solution is x = 60, y = 40
A: there were 60 chickens and 40 ducks
If you want to buy and sell, now you have 40 chickens and 48 ducks

There are 60 chickens and ducks in total. One fifth of the chickens are sold and 12 ducks are bought back. At this time, the chickens and ducks are equal. How many chickens and ducks do you have?

Let chicken = x, duck = 60-x, X (1-1 / 5) = 60-x + 12, chicken = x = 40, duck = 60-40 = 20

There are 1500 chickens and ducks in the farm. It is known that the number of chickens is 100 more than 3 / 5 of ducks. How many chickens and ducks are there in the farm

Number of ducks = (1500-100) / (1 + 3 / 5) = 875
Number of chickens = 1500-875 = 625

There are chickens, ducks and geese in the farm. The number of chickens accounts for 4 / 9 of the total. There are 1500 ducks. The ratio of ducks to geese is 3:2. How many chickens and ducks do you have?

Geese = 1500 △ 3 × 2 = 1000
Total = (1500 + 1000) / (1-4 / 9) = 4500
Chicken = 4500-1500-1000 = 2500

There are chickens, ducks, geese and chickens in the farm, accounting for 4 / 9 of the total. There are 1500 ducks. The ratio of ducks to geese is 3:2. How many chickens and geese do you have?

Geese = 1500 △ 3 × 2 = 1000
Chicken = (1500 + 1000) / (1-4 / 9) × (4 / 9) = 2000