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 ?
- (a) 21, 11 and 29 respectively
- (b) 28, 18 and 22 respectively
- (c) 37, 27 and 13 respectively
- (d) 39, 29 and 11 respectively ✓ UPSC's answer
Why the answer is (d)
• Total English speakers = 21, and both English and Hindi speakers = 10, so only English speakers = 21 - 10 = 11.
• Total students = 50, so only Hindi speakers = 50 - 11 - 10 = 29.
• Total Hindi speakers = only Hindi speakers + both speakers = 29 + 10 = 39.
• Therefore the required values are Hindi = 39, only Hindi = 29, only English = 11, which is option (d).
Why the other options are wrong
- (a) 21, 11 and 29 respectively
- Option (a) gives only English as 29, but only English must be 21 - 10 = 11.
- (b) 28, 18 and 22 respectively
- Option (b) gives only English as 22 and Hindi as 28, but only English is 11 and Hindi is 39.
- (c) 37, 27 and 13 respectively
- Option (c) gives only English as 13 and Hindi as 37, but only English is 11 and Hindi is 39.
Asked in the CSAT Paper II of the UPSC Civil Services Preliminary Examination 2014, held on 24 August 2014. Question and answer key: Union Public Service Commission. Explanation: UPSC Answer Check.