1. You can make 6 unique pairs with 1, 4, 5, and 8.
Pairs: 1+4, 1+5, 1+8, 4+5, 4+8, 5+8
Sums: 5, 6, 9, 9, 12, 13
2. After adding the pairs together, we get 6 sums. Out of these 6 sums, 4 out of 6 are greater than 7.
3. The probability will be written as 4/6. Simplify, then we get 2/3.
Answer: 2/3