Wayne goes to a fruits vendor to purchase mangoes and oranges

Wayne goes to a fruits vendor to purchase mangoes and oranges. The cost of 4 mangoes is $10, and the cost of 5 oranges is $10. If Wayne buys fruits worth $31, he has purchased at least how many mangoes?

AQuA-RAT — Algebra Question Answering with Rationales (Ling et al., DeepMind, 2017) · train #84860