Two wine merchants entered the country carrying 64 and 20 barrels of wine respectively. As they did not have enough money to pay customs duties, the first paid with 5 barrels and 40 Euros, while the second delivered 2 barrels, receiving 40 Euros as exchange.
How much does the customs tax of each barrel cost?
If we call X at the cost of the barrel e Y at the price of the customs tax, from the statement we can deduce the following system of two equations with two unknowns:
5x + 40 = 64y
2x - 40 = 20y
Solving the system we have that the price of each barrel is € 120 and the Cost of customs duties is € 10.