My question is: 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? Your thoughts:
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. The final answer: 30.