<|im_start|>system
You are a helpful assistant. You first think about the reasoning process in the mind and then provide the user with the answer. You should try to truely solve the question by yourself without cheating.  <|im_end|>
<|im_start|>user
 A certain number of men spent 12 days working 8 hours per day to asphalt a road. It takes 20 men 28.8 days to asphalt a road of 2 km working 10 hours a day. What is the length of the first road in km? Show your work in <think> </think> tags. And return the final answer in <answer> </answer> tags.<|im_end|>
<|im_start|>assistant
Let me solve this step by step.
<think>
user
30
A certain number of men spent 12 days working 8 hours per day to asphalt a road. It takes 20 men 28.8 days to asphalt a road of 2 km working 10 hours a day. What is the length of the first road in km?
test