Say I have a grid of 16 prime numbers and I need to pick 3 with which I can make 4 givrn numbers. How do I approach that problem?

No computers allowed. My approach would be brute force, but is there a smarter way?

It brings me joy this was posted (inadvertently, i am sure) in f/parenting. 

For funzies: What parental task would this describe?

i say: 16 semi fungible modes of mac’n’chz to create 4 allergen-specific meals

If the target number is even, you will need the number 2, since all other primes are odd, and the sum of three odds would be odd.

I think it's mostly brute force but there are some shortcuts like that

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