If $a$ and $b$ are positive integers such that $\gcd(a,b)=210$, $\mathop{\text{lcm}}[a,b]=210^3$, and $a < b$, how many possible values are there for $a$?
The possible values of a are 2, 3, 5, 7, for a total of 4 possible values.
can you please explain how you got that answer
and you answer is completly incorrect
