how to take 1,3,5 columns of {{1,2,3,4,5},{2,1,3,4,5},{2,3,1,4,5}}
In[137]:= l = {{1, 2, 3, 4, 5}, {2, 1, 3, 4, 5}, {2, 3, 1, 4, 5}}; In[138]:= l[[All, {1, 3, 5}]] Out[138]= {{1, 3, 5}, {2, 3, 5}, {2, 1, 5}}