SOLUTION: Alison paid $285 for 5 similar dvds and 9 similar cds. Janice paid $225 for 5 similar dvds and 5 similar cds. How much did Suzy pay for 5similar dvds and 6 similar cds?

Algebra ->  Equations -> SOLUTION: Alison paid $285 for 5 similar dvds and 9 similar cds. Janice paid $225 for 5 similar dvds and 5 similar cds. How much did Suzy pay for 5similar dvds and 6 similar cds?      Log On


   

Question 1096562: Alison paid $285 for 5 similar dvds and 9 similar cds. Janice paid $225 for 5 similar dvds and 5 similar cds. How much did Suzy pay for 5similar dvds and 6 similar cds?
Answer by ikleyn(52780) About Me  (Show Source):
You can put this solution on YOUR website!
.
It follows directly from the condition that 4 cds cost $285 - $225 = $60.


Hence, 1 cd costs 60/4 = 15 dollars.


Then 5 dvds cost 225 - 5*15 = 150 dollars and 1 dvd costs 30 dollars.


From this point you can easily complete the solution on your own.


The lesson to learn from the solution is THIS: 

    You NEITHER need solve the system of equations NOR a single equation to get the answer.

    With the given condition, you can solve the problem MENTALLY.