### **Strategy Analysis and Group Optimization**
---
#### **Strategy One: Fixed 20 Yuan Daily**
- **Expected profit per trade**：
\[
(0.9 \times 20) - (0.1 \times 20) = 16 \ \text{Yuan}
\]
- **Total monthly profit**：
\[
16 \times 30 = 480 \ \text{Yuan}
\]
---
#### **Strategy Two: Group Rolling Trading**
Divide the initial capital of 600 Yuan into **10 groups**, each group **60 Yuan**, with a maximum of **3 trades** per group, the rules are as follows:
1. **Profit Path** (three consecutive profits):
- Day 1: 60 → 120 Yuan
- Day 2: 120 → 240 Yuan
- Day 3: 240 → 480 Yuan
- **Total profit**：480 - 60 = **420 Yuan**
- **Probability**：\(0.9^3 = 0.729\)
2. **Loss Path** (loss on any day):
- Probability of loss on day 1: \(0.1\), loss of 60 Yuan
- Probability of loss on day 2: \(0.9 \times 0.1 = 0.09\), loss of 60 Yuan
- Probability of loss on day 3: \(0.9^2 \times 0.1 = 0.081\), loss of 60 Yuan
- **Total failure probability**：\(0.271\), loss of 60 Yuan
**Expected profit per group**：
\[
(0.729 \times 420) + (0.271 \times -60) = 306.18 - 16.26 = 289.92 \ \text{Yuan}
\]
**Total profit for 10 groups**：
\[
289.92 \times 10 = 2,\!899.2 \ \text{Yuan}
\]
---
### **Conclusion**
1. **Strategy Selection**：
The second strategy (group rolling trading) is clearly better, with an expected profit of **2,899 Yuan**, far exceeding the **480 Yuan** of strategy one.
2. **Grouping Plan**：
- Divide 600 Yuan into **10 groups**, each with an initial **60 Yuan**.
- Each group can trade a maximum of **3 times**, and if a loss occurs midway, trading must stop immediately.
- Profits are reinvested on successful paths, while losses only affect the initial capital.
---
**Answer**：
Should choose **the second strategy**, grouping in **10 groups**, each with an initial 60 Yuan, maximum of 3 trades, with an expected monthly profit of about **2,900 Yuan**.