Problema Solution
Outside a local Wal-Mart, Girl Scout cookies are being sold at $3:50$ per box. The number of boxes
of Trefoils sold is three more than the number of boxes of Samoas sold. The number of boxes of
Tagalongs sold is the sum of the number of boxes of Trefoils and Samoas sold. The total amount
raised from the cookie sale is $161$. How many of each type of cookie was sold?
Answer provided by our tutors
let
$3.5 per Girl Scout box
x = number of boxes of Trefoils sold
y = number of boxes of Samoas sold
z = number of boxes of Tagalongs sold
number of boxes of Trefoils sold is three more than the number of boxes of Samoas sold
x = y + 3
number of boxes of Tagalongs sold is the sum of the number of boxes of Trefoils and Samoas sold
z = x + y
total amount raised from the cookie sale is $161
3.5(x + y + z) = 161
by solving the system
x = y + 3
z = x + z
3.5(x + y + z) = 1615
we find
x = 13 boxes of Trefoils sold
y = 10 boxes of Samoas sold
z = 23 boxes of Tagalongs sold