Answer :
In thirty days. The least common multiple of the two is 30 (5x6), and this would be the next day that you would have both.
make a list
5th day so
5,10,15,20,25,30,35,40
6th day is
6,12,18,24,30
the correponding day is 30 so the answer is 30
5th day so
5,10,15,20,25,30,35,40
6th day is
6,12,18,24,30
the correponding day is 30 so the answer is 30