None of these will do the trick.
13+12-6-2 will however be 17.
No
You can add any one of 13, 15, 17, 19 and 21.
-1
-287
12+13+14 :D * * * * * Sadly, not correct. They add to 39. Try 11 + 12 + 13 instead. or 35.9 and 0.1
25
-1
11, 12 and 13
They are 11, 12 and 13.
-13
No two of those numbers add up to 17.
11+12+13=36