A pencil costs $0.5 each and a folder costs $0.9 each. An office needs two dozen pencils and 20 pieces of folders. How much does it cost to buy the office supplies? Give me reasons, before answering the question
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Two dozens of pencils are equal to 2 x 12 = 24 pencils. So the total cost of pencils is $0.5 x 24 = $12. The total cost of folders is $0.9 x 20 = $18. Thus, the cost to buy the office supplies is $12 + $18 = $30. So the final answer is 30.
Assistant