|
5 |
6 |
7 |
8 |
9 |
10 |
11 |
12 |
13 |
14 |
15 |
| 5 |
X |
11 |
12 |
13 |
14 |
15 |
16 |
17 |
18 |
19 |
20 |
| 6 |
11 |
X |
13 |
14 |
15 |
16 |
17 |
18 |
19 |
20 |
21 |
| 7 |
12 |
13 |
X |
15 |
16 |
17 |
18 |
19 |
20 |
21 |
22 |
| 8 |
13 |
14 |
15 |
X |
17 |
18 |
19 |
20 |
21 |
22 |
23 |
| 9 |
14 |
15 |
16 |
17 |
X |
19 |
20 |
21 |
22 |
23 |
24 |
| 10 |
15 |
16 |
17 |
18 |
19 |
X |
21 |
22 |
23 |
24 |
25 |
| 11 |
16 |
17 |
18 |
19 |
20 |
21 |
X |
23 |
24 |
25 |
26 |
| 12 |
17 |
18 |
19 |
20 |
21 |
22 |
23 |
X |
25 |
26 |
27 |
| 13 |
18 |
19 |
20 |
21 |
22 |
23 |
24 |
25 |
X |
27 |
28 |
| 14 |
19 |
20 |
21 |
22 |
23 |
24 |
25 |
26 |
27 |
X |
29 |
| 15 |
20 |
21 |
22 |
23 |
24 |
25 |
26 |
27 |
28 |
29 |
X |
In the table above, the green boxes show all the even sums made by adding numbers between 5 and 15. Take any particular row and column and look at the box where the row and column meet. If it contains a green number then the sum of the row number and column number is even. For example, row 8 and column 10 meet at 18 (green), as do row 10 and column 8.