Answer:Here's how to solve this: 1. Find the cost of one item:If 3 items cost 100, then one item costs 100 / 3 = 33.33 (approximately) 2. Calculate the cost of 12 items:Multiply the cost of one item by 12: 33.33 * 12 = 399.96 Therefore, 12 items will cost approximately 399.96.