Question

A store is having a sale on 200 dvd movies.some of the movies are being sold for $10 and some are being sold for $12.if the store made $2200 after selling all 200 dvds,how many $12 dvds were sold?

Answer 1

X = $ 10 dvd's.....y = $ 12 dvd's

x + y = 200....x = 200 - y
10x + 12y = 2200

10(200 - y) + 12y = 2200
2000 - 10y + 12y = 2200
-10y + 12y = 2200 - 2000
2y = 200
y = 200/2
y = 100 ....so there were 100 $ 12 dvd's sold