Problema Solution
The cost of 11 CD's and 12 DVD's is $150.62 and th cost of 1 DVD and 12 CD's is $116.07. How much does a CD and a DVD cost?
Answer provided by our tutors
Let the cost od CD be c and DVD be d. So, 11c+12d = 150.62. And d+12c = 116.07.
SOlving the two equations:
d = 116.07-12c.
11c+12(116.07-12c) = 150.62.
So, 11c -144c = 150.62 - 116.07*12 = 1770.22.
So c= $ 9.34.
So, d = 116.07-12*9.34 = $ 3.99