Posted by Liz on .
My friend and I are both going to start working. I'm starting Sunday and will have every 9th day off. She's starting Monday (the day after me) and will have every 6th day off. When is the first day we'll both have off to go to the mall? I'll need the formula along with the name of the day. Thanks.

Math 
bobpursley,
Sun MTWTFS Sun MTWTFSat SunMTWTHS
Her days off, 2Mon, 3Wed, 4Fri, 5Sun...
Your days off, 1Sat, 2Fri, 3Thur, 4Wed,
so, extend this out to get a common day.
the numbers is the week
9Wed is the ninth week, wednesday, for instance.