Question

Brian Smith sells sets of movie posters ($12) and baseball cards ($8) at a local flea market. On last Sunday, Brian’s total sales were $840. People bought four times as many movie posters as baseball cards. How much did Brian make on the movie posters?

Answer 1

Assume that you sold x baseball cards. This means that you sold 4x movie posters. So if he made $840, then he got 8x dollars on the baseball cards and 4x*12=48x dollars on movie posters. Adding 8x and 48x should be 840. So 56x=480. This means that x=15. So if Brian made 48x dollars on movie posters, it's really 48*15=720. Therefore, Brian made $720 on the movie posters.