Calculate LCM of Denominators: Finding the Least Common Multiple of 3, 5, and 7

The least common multiple (LCM) of $5, 7, \text{ and } 3$ is the smallest positive integer that is divisible by each of these numbers.

First, calculate the LCM by multiplying the numbers, as they are all prime:

LCM is $5 \times 7 \times 3 = 105$.

So the least common multiple is $105$.