Question

Four CDs and 4 DVDs cost $164. The cost of the 4 CDs is half the cost of the
4 DVDs. What is the cost of each CD?

Answer 1

Answer:

$13.67

Step-by-step explanation:

Let's say that CD= c and DVDs= d. Four CDs and 4 DVDs cost $164, so the equation will be:

i.  4c + 4d= 164

The cost of the 4 CDs is half the cost of the  4 DVDs, to put into an equation it will be:

ii.   4c= 0.5(4d)

     4c= 2d

     d= 2c

Then we can substitute the second equation (ii) into the first equation (i). The calculation will be:

4c + 4d= 164

4c + 4(2c)= 164

4c+ 8c= 164

12c= 164

c=13.67

The cost for each CD is $13.67