2024 CSAT, all questions
UPSC Prelims 2024 · CSAT
Question 28: Basic Numeracy
In an examination, 80% of students passed in English, 70% of students passed in Hindi and 15% failed in both the subjects. What is the percentage of students who failed in only one subject?
a15%
b20%
c25%
d35%
AnswerUPSC’s answer is (b).
Failed in English: 100 − 80 = 20%. Failed in Hindi: 100 − 70 = 30%. Failed in both: 15%. Failed only in English = 20 − 15 = 5%; failed only in Hindi = 30 − 15 = 15%. Failed in exactly one subject = 5 + 15 = 20%. Remember: 'only one' excludes the group that failed both subjects.
Why each option is right or wrong
- (a) Wrong. 15% is the number who failed in both subjects.
- (b) Right. 5% (English only) + 15% (Hindi only) = 20%.
- (c) Wrong. 25% matches no group: English only is 5%, Hindi only 15%, both 15%.
- (d) Wrong. 35% is the share failing at least one subject, including the 15% who failed both.
Answer: UPSC’s key. Explanation: written by UPSC Grade, not by UPSC.
Source: UPSC, Civil Services (Preliminary) Examination 2024, General Studies Paper II (CSAT), Series A. The paper on upsc.gov.in.