I'm stuck on this math problem: Mr. Callen bought 10 paintings at $40 each and 8 wooden toys at $20 each from the crafts store to resell at a profit. However, when he sold the items, the selling price of a painting was 10% less and the selling price of a hat 15% less. Calculate the total loss Mr. Callen made from the sale of the items.
Can you help?