To break it down they will only be able to meet every 4th week.
Identify and explain the error
The error is they would meet in two weeks.
The wouldn’t be possible because Lisa goes every 4 weeks. In two weeks only Beth would go.
Correct Solution-
The correct solution is 4 weeks. He correct solution is 4 weeks because since Beth goes every two weeks and Lisa goes again in 4 weeks. Because two is a multiple of 4.
Share a strategy-
The strategy I would is just use every 4th week.
Ex.
Beth: 2, 4,6, 8…
Lisa: 4,8, 12…..
I’m this example they would meet the 4th week, 8th week, and 12th week.
Hope this made since.