George sold 3 cars, so he earned 3 cars * $5/car = $<<3*5=15>>15 from them.

The lego set cost was then $45 - $15 = $<<45-15=30>>30.

# Answer

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<|im_start|>system
You are a helpful assistant.<|im_end|>
<|im_start|>user
George was selling some of his old toys on the internet. He managed to sell 3 little cars and a set of Legos. In total, he earned $45. How much did the Legos set cost, if one little car was sold for $5?
Please reason step by step, and put your final answer within \boxed{{}}.<|im_end|>
<|im_start|>assistant

user
30
George was selling some of his old toys on the internet. He managed to sell 3 little cars and a set of Legos. In total, he earned $45. How much did the Legos set cost, if one little car was sold for $5?
train