for every 8cds sold, there were 12 dvds sold. a combined total of 70 cds and dvds were sold. how many cds were sold that day? write a proportion to show the relationship and solve it to find the number so cds sold
d = (12/8) c = (3/2) c
or
d/c = 3/2
d + c = 70 so d = 70 -c
so
(70 -c )/c = 3/2
70 - c = 3 c / 2
140 - 2 c = 3 c
5 c = 140
c = 28
To find the number of CDs sold, we can set up a proportion using the given information.
Let's set up the proportion:
CDs sold (x) / DVDs sold = Total CDs / Total DVDs
According to the information given, for every 8 CDs sold, there were 12 DVDs sold. Therefore, the proportion becomes:
x / 12 = 70 / (8 + 12)
Now, let's solve for x using cross-multiplication:
x = (12 * 70) / (8 + 12)
x = 840 / 20
x = 42
Therefore, 42 CDs were sold that day.