For this question, there are 2 possible answers. My possible answers are: 8, 7, 13, 10, 6, 12, 9 and 6, 9, 11, 12, 4, 14, 7. For this question, on rule is that the only numbers that are allowed are 1-15 and another rule is that numbers cannot be repeated. This is how I found the possible answers for this question. My strategy that I did was Make a List.
The first clue is:'The numbers on the first 2 cards add up to 15.' I listed all the possible answers that add up to 15. These are all the formulas that add up to 15 (that are the numbers 1-15):
1+14, 2+13, 3+12, 4+11, 5+10, 6+9, 7+8, 8+7, 9+6, 10+5, 11+4, 12+3, 13+2, 14+1
The second clue is:'The numbers on the second and third cards add up to 20.' I listed all the possible answers that add up to 20. These are all the formulas that add up to 20 (that are the numbers 1-15):
5+15, 6+14, 7+13, 8+12, 9+11, 11+9, 12+8, 13+7, 14+6, 15+5
The third clue is:'The numbers on the third and fourth cards add to 23.'I listed all the possible answers that add up to 23. These are all the formulas that add up to 23 (that are the numbers 1-15):