P1 owes $90, P1 pays $70 so he still owes $20, he took out another loan for $80 so now he owes $100, but then he pays $100, whats does that equal?
His debt is $0.
Here are the numbers you gave me:
90-70= 20 | 20+80=100 | 100-100= 0
So how can you come to the conclusion that Person one gave $10 more when the numbers don't say so? Or did you give me the wrong numbers?