In an examination 80% of candidates passed in English and 85% of candidates passed in Mathematics. If 73% of candidates passed in both subjects then what percentage of candidates failed in both subjects:

In an examination 80% of candidates passed in English and 85% of candidates passed in Mathematics. If 73% of candidates passed in both subjects then what percentage of candidates failed in both subjects:
Answer: 8

Using the inclusion-exclusion principle the percentage of candidates passing at least one subject is 80% + 85% - 73% = 92%. Thus 100% - 92% = 8% failed both subjects. Studying this problem enhances understanding of set theory and percentage calculations.