Not sure what question you're talking about so I answered the jewelry store one.
Set up an equation like this where x is the number of groups:
x =
Now just solve the equation by dividing by (or multiplying by the reciprocal: 6).
x = 27/5 = 5 and 2/5ths
Since you can't have 5 and 2/5ths groups, the answer is just the biggest number of groups that could be made without resorting to a fraction.
So just 5 groups..