What was the question for this implicit rationale, and corresponding answer?
James earns 20 * .2 = $4 less while working his second job. So he earns 20 - 4 = $16 an hour. At his first job he earns 20 * 30 = $600. He works 30 / 2 = 15 hours at his second job. So he earns 15 * 16 = $240. So he earns 600 + 240 = $840 a week.
 The answer: 840
The question: James earns $20 an hour while working at his main job. He earns 20% less while working his second job. He works 30 hours at his main job and half that much at his second job. How much does he earn per week?