We have 12 km / 3 km = <<12/3=4>>4.

So, the distance covered in 12 km is 4 times greater than 3 km.

The time taken will also be 4 times greater.

So, 2 hours x 4 = <<2*4=8>>8 hours.

We convert the time to minutes: 8 hours * 60 minutes/hour = <<8*60=480>>480 minutes.

# Answer

480
<|im_start|>system
You are a helpful assistant.<|im_end|>
<|im_start|>user
To make 3 km, Ben walked for 2 hours. Continuing at the same speed, how much time in minutes would it take him to travel 12 km?
Please reason step by step, and put your final answer within \boxed{{}}.<|im_end|>
<|im_start|>assistant

user
480
To make 3 km, Ben walked for 2 hours. Continuing at the same speed, how much time in minutes would it take him to travel 12 km?
train