Gabriela needs to sell 4 more cups of coffee to make a profit of $75.
She sells 90 cups and makes $0.80 profit on each cup. That equals $72 profit.
90 x $0.80= $72
She wants to make $75 profit.
$75 - $72 = $3 profit short for the day
$3/$0.80 = 3.75 cups of coffee short so to make her profit she must sell a total of 94 cups of coffee for the day or an additional 4 cups.