Ross and Annie do chores at their home acreage. Ross mows the acreage lawn every 12 days, and Annie bathes the dog every 21 days. If Ross and Annie do their chores today, how many days will pass before they both do their chores again on the same day?

84 days will pay before they both do their chores again on the same day.

Ross mows the lawn Annie bathes the dog

12 x 1 = 12 21 x 1 = 21

12 x 2 = 24 21 x 2 = 42

12 x 3 = 36 21 x 3 = 63

12 x 4 = 48 21 x 4 = 84

12 x 5 = 60 21 x 5 = 105

12 x 6 = 72 21 x 6 = 126

12 x 7 = 84 21 x 7 = 147

12 x 8 = 96 21 x 8 = 168

12 x 9 = 108 21 x 9 = 189

12 x 10 = 120 21 x 10 = 210