human
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?
assistant
How much did the cars cost? ** George sold 3 cars, so he earned 3 cars * $5/car = $<<3*5=15>>15 from them.
How much did the Legos set cost? ** The lego set cost was then $45 - $15 = $<<45-15=30>>30.
#### 30