UPSC Prelims 2012 · CSAT
Question 22: Logical Reasoning and Mental Ability
Read the passage given below and the two statements that follow (given on the basis of the passage) : Four men are waiting at Delhi airport for a Mumbai flight. Two are doctors and the other two are businessmen. Two speak Gujarati and two speak Tamil. No two of the same profession speak the same language. Two are Muslims and two are Christians. No two of the same religion are of the same profession, nor do they speak the same language. The Tamil-speaking doctor is a Christian.
- 1.The Christian-businessman speaks Gujarati.
- 2.The Gujarati-speaking doctor is a Muslim.
Which of the above statements is/are correct conclusion/conclusions ?
AnswerUPSC’s answer is (c).
Each profession has one Gujarati and one Tamil speaker, and each religion has one doctor, one businessman, one Gujarati and one Tamil speaker. The Tamil-speaking doctor is a Christian, so the other doctor, who speaks Gujarati, must be a Muslim: statement 2 is right. The Christian businessman cannot share a language with the Christian doctor, who speaks Tamil, so he speaks Gujarati: statement 1 is right. Remember: lay out profession, language and religion in a grid, then deduce.
- 1. The Christian businessman cannot share the Christian doctor's Tamil, so he speaks Gujarati.
- 2. The Tamil-speaking doctor is Christian, so the Gujarati-speaking doctor has the other religion, Muslim.
How you could have got this
- If you were sure statement 1 is correct, (b) and (d) go: each of them leaves 1 out.
What you needed to know: The Christian businessman cannot share the Christian doctor's Tamil, so he speaks Gujarati.
- Then, if you were sure statement 2 is correct, (a) goes: it leaves 2 out.
What you needed to know: The Tamil-speaking doctor is Christian, so the Gujarati-speaking doctor has the other religion, Muslim.
Only (c) is left. This one needs every statement.
Which options go is worked out from UPSC’s key and the options, not by a model.
Why each option is right or wrong
- (a) Wrong. Statement 2 is also correct.
- (b) Wrong. Statement 1 is also correct.
- (c) Right. Both statements follow from the rules.
- (d) Wrong. Both statements follow.
Answer: UPSC’s key. Explanation: written by UPSC Grade, not by UPSC.
Source: UPSC, Civil Services (Preliminary) Examination 2012, General Studies Paper II (CSAT), Series A. The paper on upsc.gov.in.