40039

firstly I found out all of the possibilities for the 1st and 2nd number cards, e.g 1-14 2-13 3-12. I then used the 2nd number in each possibility that I had used to figure out the possible 3rd number cards. I carried on doing this until had my final answers. some of my sequences hadn't worked because the number I was going to use was bigger than the actual total that I had to make,so I was only left with 6-9-11-12-4-14-7, 7-8-12-11-5-13-8, 9-6-14-9-7-11-10, and 8-7-13-10-6-12-9. I figured out that in the 2nd and 3rd sequences I had the same numbers twice, and only having the numbers 1-15 once that wouldn't work, so I was left with my two solutions that were correct.