Problem:
Juan organizes the stamps in his collection by country and by the decade in which they were issued. The prices he paid for them at a stamp shop were: Brazil and France, 6¢ each, Peru 4¢ each, and Spain 5¢ each. (Brazil and Peru are South Americal countries and France and Spain are in Europe.)
Number of Stamps by DecadeCountryBrazilFrancePeruSpain​’50s4863​’60s7449​’70s1212613​’80s815109​​Juan’s Stamp Collection
His South American stamps issued before the ′70s cost him
Answer Choices:
A. $0.40
B. $1.06
C. $1.80
D. $2.38
E. $2.64
Solution:
His South American stamps issued before the ′70s include 4+7=11 from Brazil that cost 11×$0.06=$0.66 and 6+4=10 from Peru that cost 10×$0.04=$0.40. Their total cost is $0.66+$0.40=$1.06.
Answer: B​.
The problems on this page are the property of the MAA's American Mathematics Competitions