UPSC Prelims 2017 · CSAT
Question 32: Basic Numeracy
In a city, 12% of households earn less than ₹ 30,000 per year, 6% households earn more than ₹ 2,00,000 per year, 22% households earn more than ₹ 1,00,000 per year and 990 households earn between ₹ 30,000 and ₹ 1,00,000 per year. How many households earn between ₹ 1,00,000 and ₹ 2,00,000 per year?
AnswerUPSC’s answer is (b).
Over ₹2,00,000 is 6% and over ₹1,00,000 is 22%, so between ₹1,00,000 and ₹2,00,000 is 22 - 6 = 16%. Under ₹30,000 is 12%, so between ₹30,000 and ₹1,00,000 is 100 - 12 - 22 = 66%. This 66% is 990 households, so the total is 990 / 0.66 = 1500. The 16% band is 0.16 x 1500 = 240.
How you could have got this
No shortcut here: in a “how many” question, ruling out options doesn’t help. Every statement has to be judged.
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) 250 is not 16% of 1500.
- (b) Correct: 16% of 1500 = 240.
- (c) 230 is not 16% of 1500.
- (d) 225 is 15% of 1500, not 16%.
Answer: UPSC’s key. Explanation: written by UPSC Grade, not by UPSC.
Source: UPSC, Civil Services (Preliminary) Examination 2017, General Studies Paper II (CSAT), Series A. The paper on upsc.gov.in.