Create two groups of cards with the SAME SUM using as many cards as possible using the numbers 8 7 6 2 1 3.

Explained below.

Step-by-step explanation:

In this case we need to form two group of cards (consisting of any number of cards) having the same sum using the cards numbered as 8, 7, 6, 2, 1, 3.

The possible groups are as follows:

Group 1               Group 2                    Sum

{8, 1}                      {7, 2}                         9

{8, 2}                     {7, 3}                         10

{8, 3}                     {7, 3, 1}                      11

{8, 1, 3}                  {7, 3, 2}                     12

{8, 2, 3}                 {7, 2, 1, 3}                  13

{8, 3, 2, 1}              {7, 6, 1}                      14

And so on.

2+2=4

4-5=-1

is that your