Practice UPSC CSAT previous year questions from 2011–2026 classified underSet Theory. Review the original question, four options, correct answer and explanation for every PYQ.
4 questions • 2011–2026
Out of 130 students appearing in an examination, 62 failed in English, 52 failed in Mathematics, whereas 24 failed in both English and Mathematics. The number of students who passed finally is
Failed in at least one = 62+52−24=90. Therefore passed = 130−90=40.
There are 50 students admitted to a nursery class. Some students can speak only English and some can speak only Hindi. 10 students can speak both English and Hindi. If the number of students who can speak English is 21, then how many students can speak Hindi, how many can speak only Hindi and how many can speak only English?
Of 50 students, 21 speak English and 10 speak both, so 11 speak only English. The remaining 29 speak only Hindi, giving 39 Hindi speakers.
Out of a total of 120 musicians in a club, 5% can play all the three instruments, guitar, violin and flute. It so happens that the number of musicians who can play any two and only two of the above instruments is 30. The number of musicians who can play the guitar alone is 40. What is the total number of those who can play violin alone or flute alone?
6 musicians play all three; 30 play exactly two; 40 play guitar alone. From the total of 120, the combined violin-alone and flute-alone count is 44.
There are 100 students in a particular class. 60% students play cricket, 30% students play football and 10% students play both the games. What is the number of students who play neither cricket nor football?
At least one game = 60+30−10 = 80%. Therefore 20% play neither = 20 students.
Attempt questions one by one with UPSC-style marking and immediate explanations.