If a and b are distinct positive integers

If a and b are distinct positive integers. The units digit of a^2 is equal to the units digit of a, and the units digit of b^2 is equal to the units digit of b. If the units digit of a·b is equal to neither the units digit of a nor the units digit of b, then what is the units digit of a·b?

AQuA-RAT — Algebra Question Answering with Rationales (Ling et al., DeepMind, 2017) · train #29361