| 60 | + | 1 4 | ( | t | − | 200 | ) | = | 100 | − | 3 10 | ( | t | − | 400 | ) |
| 方程左边 = | 60 | + | 1 4 | t | − | 1 4 | × | 200 |
| = | 60 | + | 1 4 | t | − | 50 |
| = | 10 | + | 1 4 | t |
| 10 | + | 1 4 | t | = | 100 | − | 3 10 | ( | t | − | 400 | ) |
| 方程右边 = | 100 | − | 3 10 | t | + | 3 10 | × | 400 |
| = | 100 | − | 3 10 | t | + | 120 |
| = | 220 | − | 3 10 | t |
| 10 | + | 1 4 | t | = | 220 | − | 3 10 | t |
1 4 | t | + | 3 10 | t | = | 220 | − | 10 |
11 20 | t | = | 220 | − | 10 |
11 20 | t | = | 210 |
| t | = | 210 | ÷ | 11 20 |
| = | 210 | × | 20 11 |
| t | = | 4200 11 |
| t | = | 381.818182 |