A set of numbers has an average of 20

A set of numbers has an average of 20. If the largest element is 4 greater than 3 times the smallest element, which of the following values cannot be in the set?

This problem repeats another one in the library (at most with different numbers), so it's left out of browsing.

AQuA-RAT — Algebra Question Answering with Rationales (Ling et al., DeepMind, 2017) · train #52301