A store is having a sale on 200 DVD movies some of the movie

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

Solution

lets say,

nos of dvd sold @ 12$ is = x

nos of dvd sold @ 10$ is = y

hence x+y =200.............(1)

earning from these seeling is 2200$

12x + 10y = 2200........(2)

by solving equation

x= 100

y = 100

so he sold 100, 12$ dvds