Lizzy: John repairs 5 cars. 3 of the cars take 40 minutes each to repair. The remaining ones take 50% longer each to repair. He makes $20 per hour repairing cars. How much money does he make?.
Me: Hmmm, let me think. I think this is the detailed solution:
The 3 cars take 3 * 40 = 120 minutes to make. He repairs 5 - 3 = 2 more cars. They each take 40 * .5 = 20 minutes longer per car. So they each take 40 + 20 = 60 minutes. So he repaired cars for 120 + 2 * 60 = 240 minutes. That is 240 / 60 = 4 hours. So he made 4 * 20 = $80. Final answer: 80.