周日去洗汽车，又是排队。琢磨了一下，这生意不错呀。 投或借＄５００，０００， 一周开七天，每日营业八小时，每小时洗２０部车，雇佣一位经理和八位老墨，月租＄６，０００。回报60.4%. 我没算错吧？
| Sales | |
| Operating hours per day | 8 |
| Car Washed Per Hour | 20 |
| Average price per car | 15 |
| Dailys Revenue | 2,400 |
| Monthly revenue | $ 72,000 |
| Monthly costs | |
| Rent | (6,000) |
| Utility | (6,000) |
| Manager salary | (5,200) |
| Labor costs | (17,280) |
| Supplies | (1,000) |
| Misc | (3,000) |
| Interest | (2,083) |
| Income before tax | 31,437 |
| Tax | (6,287) |
| Net monthly profit | $ 25,149 |
| Annual profit | $ 301,792 |
| Investment | 500,000 |
| ROI | 60.4% |
