SOLUTION: old navy sells t-shirts for $8.00 a piece. They run a special where you can buy 3t-shirts for $20.00. One saturday morning they sold a total of 19 t shirts for a total of 136.00 ,

Algebra ->  Coordinate Systems and Linear Equations  -> Linear Equations and Systems Word Problems -> SOLUTION: old navy sells t-shirts for $8.00 a piece. They run a special where you can buy 3t-shirts for $20.00. One saturday morning they sold a total of 19 t shirts for a total of 136.00 ,       Log On


   



Question 176796: old navy sells t-shirts for $8.00 a piece. They run a special where you can buy 3t-shirts for $20.00. One saturday morning they sold a total of 19 t shirts for a total of 136.00 , how many people took advantage of the special??



Answer by Mathtut(3670) About Me  (Show Source):
You can put this solution on YOUR website!
lets call the amount of regular and specially priced t shirts a and b respectively
:
a+3b=19.......eq 1
:
8a+20b=136....eq 2
:
lets rewrite eq 1 to a=19-3b and plug this value into eq 2
:
8(19-3b)+20b=136
:
152-24b+20b=136
:
-4b=-16
:
highlight%28b=4%29number of specialty price deals sold
:
so 4 people took advantage of the special
: