Home / Solution: The two gears will realign at their starting position after a time equal to the least common multiple (LCM) of their rotation periods. We compute $ ext{lcm}(18, 30) $.Solution: The two gears will realign at their starting position after a time equal to the least common multiple (LCM) of their rotation periods. We compute $ ext{lcm}(18, 30) $.February 22, 2026