# math

posted by .

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

• math -

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

## Similar Questions

1. ### math

John and Paul work together at a music store. In one afternoon, they sold a total of 41 CDs. If Paul sold 9 more CDs than John, how many CDs did John sell?
2. ### Math

Write and equation to match the problem situation below. Callie has 4 rimes as many CDs as she has DVDs. She has a total of 60 CDs and DVD. How many dvds, d, does callie have?
3. ### math

i need to approximate profit in this equation 3. Hot Rocks Music sells CDs. If the profit can be approximated by following equation: , where x represents the number of thousands of CDs sold. Approximately, how many CDs must be sold …
4. ### Math

A DVD producer has fixed costs (factory, machinery, and money paid to the recording artist) of \$406,000. Additionally, for every DVD produced, the company spends \$5 for materials and labor. The DVDs can be sold for \$12 each. a) Define …
5. ### Algebra

Natalie earns \$2.50 for each CD she sells and \$3.50 for each DVD she sells. Natalie sold 45 DVDs last year. She earned a total of \$780 last year selling CDs and DVDs. Write an equation that can be used to determine the number of CDs …
6. ### Algebra

Natalie earns \$2.50 for each CD she sells and \$3.50 for each DVD she sells. Natalie sold 45 DVDs last year. She earned a total of \$780 last year selling CDs and DVDs. Write an equation that can be used to determine the number of CDs …
7. ### Math

Belmont Records produces DVD records. The fixed costs for producing a record are \$160,000, and unit cost amount to 85 cents per record. The revenue is \$5 per DVD. (a) How many DVDs must be sold in order to break even?
8. ### Calc

In the first three days of its launch, the Galaxy Music Store sold 14 CDs of album x, 8 of album y, and 6 of album z through Branch A. Through Branch B, the store sold 7 CDs of album x, 13 of album y, and 4 of album z. Branch C sold …
9. ### algebra1

juan's band produced a number of CDs to sell at a gig.the batch of CDs cost \$170.00 to make and each CD was sold for \$2.50 more than it cost to produce.juan gave 2 CDs to his friends,but sold the rest for a total of \$198.00.How many …
10. ### algebra

A store sold 60 DVDs. Some of these were on sale and sold for \$4.95 each, while the rest priced at \$5.95 each. If the sales receipts for DVDs at the end of the day totaled \$317.00, how many of each type were sold?

More Similar Questions