It looks like you're trying to calculate the probability of students taking only Computer classes based on the given numbers. However, let's clarify the situation step by step.
1. **Total Students**: 40
2. **Students taking Maths**: 14
3. **Students taking Computer**: 29
4. **Students taking both Maths and Computer**: 3
From this information, we can determine the following:
- **Students taking only Computer**:
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\text{Students taking