Least Common Multiple of 5, 15 and 25 by Listing Multiples

Multiples of 5: 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, …
Multiples of 15: 15, 30, 45, 60, 75, 90, 105, …
Multiples of 25: 25, 50, 75, …
LCM(5, 15, 25) = 75