Question 10
Jacky collects stamps from Brazil, France, Peru, Spain. Each Brazilian or French stamp costs 6 cents, each Peruvian stamp 4 cents, and each Spanish stamp 5 cents. The numbers for decades 50 s, 60 s, 70 s, 80 s are Brazil(4, 7, 12, 8), France(8, 4, 12, 15), Peru(6, 4, 6, 10), Spain(3, 9, 13, 9). Brazil and Peru are South American; France and Spain are European. How many European stamps from the 80 s did he collect?