UPSC Prelims 1999 · General Studies
Question 135: Basic Numeracy
In a town 25% families own a phone and 15% own a car. 65% families own neither a phone nor a car. 2000 families own both a car and a phone. Consider the following statements in this regard: I. 10% families own both a car and a phone. II. 35% families own either a car or a phone. III. 40,000 families live in the town. Which of the above statements are correct?
AnswerThe answer is (c).
Take the town as 100 per cent. Neither a phone nor a car: 65 per cent, so 35 per cent own at least one (II is true). Both = phone + car - either = 25 + 15 - 35 = 5 per cent, not 10 per cent (I is false). If 5 per cent of families is 2000, the town has 2000 / 0.05 = 40,000 families (III is true). So II and III are correct.
- I. Both = 25 + 15 - 35 = 5 per cent, not 10 per cent.
- II. 100 - 65 = 35 per cent own a car or a phone.
- III. 5 per cent of the town is 2000 families, so the town has 40,000.
Why each option is right or wrong
- (a) Wrong. I is false: both is 5 per cent.
- (b) Wrong. I is false.
- (c) Right. II and III.
- (d) Wrong. I is false.
Explanation: written by UPSC Grade, not by UPSC.
Source: UPSC, Civil Services (Preliminary) Examination 1999, General Studies. UPSC's own paper isn't online; the words are from a published compilation. The paper on upsc.gov.in.