UPSC Prelims 2013 · CSAT
Question 63: Basic Numeracy
Out of 120 applications for a post, 70 are male and 80 have a driver’s license. What is the ratio between the minimum to maximum number of males having driver’s license ?
AnswerUPSC’s answer is (c).
Of 120 applicants, 70 are male, so 50 are female, and 80 hold a licence. Minimum: even if all 50 females hold licences, at least 30 licence holders must be male. Maximum: all 70 males could hold licences, since 70 is below 80. So the ratio of minimum to maximum is 30 : 70 = 3 : 7. For overlap questions, find the forced minimum and the possible maximum separately.
Why each option is right or wrong
- (a) Wrong. 1 to 2 would need a minimum of 35, but the forced minimum is 30.
- (b) Wrong. 2 to 3 would need a minimum of about 47.
- (c) Right. 30 : 70 = 3 : 7.
- (d) Wrong. 5 to 7 would need a minimum of 50.
Answer: UPSC’s key. Explanation: written by UPSC Grade, not by UPSC.
Source: UPSC, Civil Services (Preliminary) Examination 2013, General Studies Paper II (CSAT), Series A. The paper on upsc.gov.in.