What 3 numbers is the sum of 15?

Answer 1

There are an infinite number of triplets.

Start with positive integers: 1 + 2 + 12, 1 + 3 + 11, etc

Then introduce negative integers: 1 + 16 - 2, 1 + 17 - 3, etc

Next try some rational fractions: 1 + 1.1 + 12.9, 1 + 1.2 + 12.8 etc

and then negatives and rational fractions: 1 + 16.1 - 2.1, 1 + 17.1 - 3.1 etc

Finally some irrationals: [1 + sqrt(3)] + [1 - sqrt(3)] + 13, etc

Each one of these groups (except the first) has an infinite number of possible solutions.