1. Yes 10 Step , Xiao Ming can climb one or two steps at a time , Excuse me? , Climb to 10 Step , Xiao Ming has （） Seed climbing method
Inductive reasoning ： Fibonacci
Total steps Total climbing method
1 1
2 2
3 3
4 5
··· ···
n F(n-1)+F(n-2)(n>=3)
2. A recent survey shows , In recent years, among the high-income people in a city , Local occupation 70% above , This fully shows that it is quite difficult for foreigners to get high income in the city .
Which of the following is true , In order to support the above conclusion ?
A： The proportion of outsiders in the total population of the city is as high as 40%
B： The proportion of outsiders in the total population of the city is insufficient 30%
C： Among the low and middle income people in the city , Foreign occupation 40%
D： Among the low and middle income people in the city , Lack of local people 30%
“ Lack of local people in the low-income group 30%” Not equal to “ Most of the outsiders are low-income ”
example ： Low and middle income people 10000 people , native 3000, Outsider 7000; High income people 1000000, native 700000, Outsider 300000; Can you tell me that it is difficult for foreigners to get high income in this area ? Total number of outsiders 7000+300000=307000, The proportion of high income of foreigners in the total number of foreigners 97.7%..
So if you want to draw a conclusion , It is necessary to know the population composition of the city , That is to say, the proportion of the population of foreigners and natives , choose A.
Technology
Daily Recommendation