Correct Option (2)
To determine the percentage of students who failed in only one subject, the following steps are undertaken:
- First, calculate the percentage of students who failed in each subject:
- Percentage failed in English = 100% - (Percentage passed in English) = 100% - 80% = 20%.
- Percentage failed in Hindi = 100% - (Percentage passed in Hindi) = 100% - 70% = 30%.
- Next, account for the students who failed in both subjects to isolate those who failed exclusively in one subject:
- Percentage failed in only English = (Percentage failed in English) - (Percentage failed in both subjects) = 20% - 15% = 5%.
- Percentage failed in only Hindi = (Percentage failed in Hindi) - (Percentage failed in both subjects) = 30% - 15% = 15%.
- Finally, sum the percentages of students who failed in only English and only Hindi to find the total percentage of students who failed in only one subject:
- Total percentage failed in only one subject = 5% (only English) + 15% (only Hindi) = 20%.
Incorrect Options:
Options 1 (15%), 3 (25%), and 4 (35%) are incorrect. Option 1 (15%) represents the percentage of students who failed in both subjects, not exclusively in one. The calculated percentage of students who failed in only one subject is 20%, which does not correspond to the values presented in options 3 or 4.