I am not too sure I understand the question or that we know enough.
Does the "refused" cofee go to the next person? Do they still prepare it and if yes, does it count as "distributed?
As far as I can see it now: from what we know they disrtibute 16-12=4 so only four copies. This is the best answer i can give with the information given.
There is not enough information to find the value of 12x and 9y.
The length is 18cm you multiply 19 by 2
Answer: x= -2/3
Step-by-step explanation: 0= -3x-2
Move the variable to the left and then divide both sides 3x=-2