Problema Solution
monica has 50 stamps, some worth 15 cents and some worth 20 cents. If their value is $9.50, how many of each kind does Monica have?
Answer provided by our tutors
Let number of 15 cents be x.
Then the number of 20 cents is 50-x.
Their value is 9.50 so:
15x + 20(50-x) = 950
15x + 1000 - 20x = 950
-5x + 1000 = 950
50 = 5x
x = 10
number of 15 cents = 10
number of 20 cents = 40