Three girls are selling cases of corn to earn money for a band trip. so far, emily sold 2 3/4 cases, brenda sold 4 1/4 cases and shannon sold 3 1/2 cases. how many cases of popcorn have the girls sold in all? the girls will need to sell a total of 15 cases in order to have enough for trip. they all want to sell an equal amount of the remaining cases or its parts.