Number Theory
# Greatest Common Divisor / Lowest Common Multiple

What is the least common multiple of $2$ and $3$?

What is the lowest common multiple of 39 and 65?

If the lowest common multiple of $3^a 5^b$ and $3^4$ is $3^5$, what is $3^a 5^b ?$

What is the least common multiple of 12 and 21?