1,6,3,7,9,4,5,7=17 only plus or minus can be out in between the numbers and they must stay in the order shown
EX. 1-6+3-7+9-4+5+7=17
It must equal 17
Here's a hint. Add all the numbers up first, then see what number needs to be subtracted in order to get 17. Then find a combination of numbers to add to that number and put a minus sign in front of them.
No, on second thought I don't think that method will work. I didn't test it first, but now I see the numbers will be subtracted twice. I'm not sure if there's a system for this problem or not.
Ok Chalese. I wrote the problem on a spreadsheet and checked all 256 combinations. There are 8 numbers, so that makes 2^8 = 256 combinations.
Guess what? No odd numbers are possible at all with these numbers.
These are the only possible values:
-42
I apologize for the confusion earlier. It seems that there is no combination of plus and minus operations that will result in the sum of 17 using the given numbers (1, 6, 3, 7, 9, 4, 5, 7) in the given order.
As you mentioned, you tested all 256 combinations using a spreadsheet and found that no odd numbers were possible. This suggests that there is no systematic solution for this particular problem. Sometimes, certain combinations of numbers may not have a solution based on the given conditions.
Therefore, in this case, it seems that there is no way to obtain a sum of 17 using only plus and minus operations between the numbers in the given order.