# Mysterious Unbalanced Sheets on Loans – story told by hunchbacked shopkeeper

Once there was a hunch-backed shopkeeper. And he told the following story:

“Once I lent 100 dinars, 50 to a sheik from Medina and another 50 to a merchant from Cairo.

“The sheik paid the debt in four instalments, in the amount 20, 15, 10 and 5. .. .. Note that the total of his debt balance is 50 dinars.

 1st Installment: Paid 20 & Still Owe 30 2nd installment: Paid 15 & Still Owe 15 3rd Installment: Paid 10 & Still Owe 5 4th Installment: Paid 5 & Owe 0 Total Paid 50 & Total Owe 50

“Meanwhile the merchants from Cairo also paid the debt of 50 dinars in four instalments, in the following amount: 20, 18, 3 and 9. And here is the balance sheet for his debt.

 1st Installment: Paid 20 & Still Owe 30 2nd installment: Paid 18 & Still Owe 12 3rd Installment: Paid 3 & Still Owe 9 4th Installment: Paid 9 & Owe 0 Total Paid 50 & Total Owe 51

“But note his total owed is 51 dinars”, remarked by the hunchbacked shopkeeper; apparently this should not have occurred.

Using a bit math, can you help our shopkeeper to solve the mystery?