A family consists of two grandparents, two parents and three grandchildren

A family consists of two grandparents, two parents and three grandchildren. The average age of the grandparents is 80 years, that of the parents is 35 years and that of the grandchildren is 6 years. What is the average age of family?

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 #59951