# Given a data set, how to do the following

I have the following set:$A=\{1, 2,3,4,5,6,7,8,9,10\}$ (my actual data has more than 10 points). I need to do the following three steps:

(A) Form all possible pairs of two digits in the above set, like $(1,2), (4,6)$ etc. Remember $(1,2)$ and $(2,1)$ are to be treated as different pairs. Since my actual data is big, I want Mathematica to find all these possible pairs.

(B) Then I have to put these pairs in the following expression: $\eta(x_1,x_2)= x_1+5x_2+10$ and compute the value of $\eta(x_1,x_2)$, for the pair $(x_1,x_2)$.

(C) Similarly, I have to this for all pairs and arrange the values of $\eta(x_1,x_2)$ is decreasing order.

• Look at Tuples eg Tuples[Range@10, 2] and eta@@@Tuples[Range@10, 2] – OkkesDulgerci Jul 10 '18 at 17:20
• What is the size of data? – OkkesDulgerci Jul 10 '18 at 17:21
• My actual data contains around 100 points. – H. Kenan Jul 10 '18 at 17:28
• If you don't want (1,1) then use Permutations[Range@10, {2}] – OkkesDulgerci Jul 10 '18 at 17:28
• Thank you, friends. I would appreciate if you put a slightly detailed answer. – H. Kenan Jul 10 '18 at 17:30

f[x1_, x2_] := x1 + 5 x2 + 10