Answer:
$2.64
Step-by-step explanation:
Selling them at 5 cents each ($0.05), he could sell 1 dozen buttons for
12 * $0.05 = $0.60
As he bought them at $0.38 per dozen, the profit per dozen would be
$0.60 - $0.38 = $0.22
As 12 dozen is 1 gross, the profit per gross would be
12 * $0.22 = $2.64
