1. **Problem:** In an examination, 42% of students failed in Mathematics and 52% failed in English. If 17% students failed in both subjects, find the percentage of those students who passed in both the subjects. 2. **Formula and Rules:** Use the principle of inclusion-exclusion for two sets: $$\text{Failed in Math or English} = \text{Failed in Math} + \text{Failed in English} - \text{Failed in both}$$ 3. **Calculation:** $$= 42\% + 52\% - 17\% = 77\%$$ 4. **Interpretation:** 77% students failed in at least one subject, so the percentage who passed both subjects is: $$100\% - 77\% = 23\%$$ 5. **Answer:** The percentage of students who passed in both subjects is **23%**. **Final answer:** 23