Problema Solution
Drusilla replaces the light bulb in the hall closet every 9 months and replaces the air filter every 6 months.She just replaced both this month.After how many months will she replace both the light bulb and the air filter.
Answer provided by our tutors
We need to find Least Common Multiple for 6 and 9:
6 = 2*3
9 = 3*3
LCM(6, 9) = 2*3*3
LCM(6, 9) = 18
After 18 months Drusilla will replace both, the light bulb and the air filter.