Sansa is a famous artist, she can draw a portrait and sell it according to its size. She sells an 8-inch portrait for $5, and a 16-inch portrait for twice the price of the 8-inch portrait. If she sells three 8-inch portraits and five 16-inch portraits per day, how many does she earns every 3 days?
Please reason step by step, and put your final answer within \boxed{}.
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