Five friends are sharing information about the marbles they have attempting to derive the total amount of marbles they own without disclosing to others the amount each own. They decide to do it by having two disclosing the sum of their marbles to the interested individual that is not part of the group:
John and Chuck have a total of 10
Nick and Chuck have a total of 13
Nick and Paul have a total of 15
Paul and John have a total of 12
How many they have total? Can you derive how many each one of them owns? When they meet Roger they add him to the group by modifying the last sum as follows:
Paul and Roger have a total of 14
Roger and John have a total of 8
What is the total of marbles the 5 friends have? Are they still preventing others from knowing how many marbles each of them have?
Could you explain the difference?