UPSC Prelims 1997 · General Studies
Question 139: Data Interpretation
The following table shows the per cent change in the number of sales (in rupees) at different retail stores in a given neighbourhood market in the period 1993 to 1995: Retail Store — Percent Change 1993 to 1994 — 1994 to 1995 Anshu: +10, -10 Borna: -20, +9 Calpo: +5, +12 Dilip: -7, -15 Elegant: +17, -8 If the sales at Anshu store amounted to Rs. 8 lakhs in 1993, then the number of sales (in lakhs of rupees) at that store in 1995 was
AnswerThe answer is (a).
Anshu's sales rose 10 per cent from 1993 to 1994 and fell 10 per cent from 1994 to 1995. Starting at Rs 8 lakhs: 8 × 1.10 = 8.8 lakhs in 1994, then 8.8 × 0.90 = 7.92 lakhs in 1995. A rise and a fall of the same percentage does not bring you back to the start; it leaves you 1 per cent lower.
Why each option is right or wrong
- (a) Right: 8 × 1.10 × 0.90 = 7.92 lakhs.
- (b) 8.00 comes from wrongly treating +10 and -10 per cent as cancelling.
- (c) 8.80 is the 1994 figure, not the 1995 one.
- (d) 9.68 comes from two successive 10 per cent rises.
Explanation: written by UPSC Grade, not by UPSC.
Source: UPSC, Civil Services (Preliminary) Examination 1997, General Studies. UPSC's own paper isn't online; the words are from a published compilation. The paper on upsc.gov.in.