1 minute is 60 seconds, so 4 minutes is 4 * 60 = <<4*60=240>>240 seconds.

During this time there would be 240 / 20 = <<240/20=12>>12 big crashes.

And also 240 / 10 = <<240/10=24>>24 car collisions.

So in total during 4 minutes there would be 12 + 24 = <<12+24=36>>36 accidents.

# Answer

36
<|im_start|>system
You are a helpful assistant.<|im_end|>
<|im_start|>user
Every 10 seconds, there is a car collision, and every 20 seconds there is a big crash. How many accidents overall will happen in 4 minutes?
Please reason step by step, and put your final answer within \boxed{{}}.<|im_end|>
<|im_start|>assistant

user
36
Every 10 seconds, there is a car collision, and every 20 seconds there is a big crash. How many accidents overall will happen in 4 minutes?
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