There are two sellers in the DVD market, Wen and Ahmed. If the market price were $5 per DVD, Wen would be willing to sell 10 DVDs and Ahmed would want to sell 15 DVDs. If the market price were to rise to $7, then:

When cell phones were first entering the market, they were relatively large and reception was undependable. all cell phones were essentially the same. but as the technology developed, many competitors entered, introducing features unique to their phones. today, cell phones are only a small fraction of the size and weight of their predecessors. consumers can buy cell phones with color screens, cameras, internet access, daily planners, or voice activation (and any combination of these features). the history of the cell phone demonstrates what marketing trend?