Question

In one bag there is 8000 Riel. There are 11 types of banknotes. There are two types of banknotes: 500 Riel type and 1000 Riel type. Find the number of each type of banknote.

Answer 1

x = 500 riel type

y = 1000 riel type

x + y = 11

500x + 1000y = 8000

x = 11 - y

500(11 - y) + 1000y = 8000

y = 5

x = 11 - 5

x = 6

x = 6

y = 5