Question

These cards can be sorted into three pairs, where each pair adds to the same number. What is this number? -8, 0, -6, 2, -4, -2​

Answer 1

Answer: -6

The three pairs are

• -8 and 2
• -4 and -2
• 0 and -6

All three pairs add to -6. This is something you'd do through trial-and-error.