Problema Solution
in may 2009 us first class mail rates increased to 44 cents for the first ounce plus 17 cents for each additional ounce. if sabrina spent 14.40 dollars for a total of 45 stamps of these two denominations,how many stamps of each denomination did she buy?
Answer provided by our tutors
x = 44 cent stamp
y = 17 cent stamp
x + y = 45
y = 45 - x
44x + 17y = 1440 cent
44x + 17(45 - x) = 1440
44x + 765 - 17x = 1440
x = 25 44 cent stamp
y = 45 - x
y = 45 - 25
y = 20 17 cent stamp