Question. Paul went to a shop to buy some groceries. He bought some bread for $2, butter for $3, and juice for two times the price of the bread. He had $15 for his shopping. How much money did Paul have left?
Answer. 6
What step-by-step reasoning justifies that answer?
Reasoning: The price of the juice was 2 * 2 = $4. So in total he paid for his shopping 2 + 3 + 4 = $9. That means he had 15 - 9 = $6 left.