Two dozens of pencils are equal to 2 x 12 = <<2*12=24>>24 pencils.

So the total cost of pencils is $0.5 x 24 = $<<0.5*24=12>>12.

The total cost of folders is $0.9 x 20 = $<<0.9*20=18>>18.

Thus, the cost to buy the office supplies is $12 + $18 = $<<12+18=30>>30.

# Answer

30
Question:
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?
Answer:
Let's think step by step.

user
30
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?
train