2020 CSAT, all questions
UPSC Prelims 2020 · CSAT
Question 53: Basic Numeracy
The recurring decimal representation 1·272727... is equivalent to
a13/11
b14/11
c127/99
d137/99
AnswerUPSC’s answer is (b).
Split the number: 1.272727... = 1 + 0.272727... The repeating part, 27 repeated, equals 27/99 = 3/11. So the number is 1 + 3/11 = 14/11. Check: 14 divided by 11 is 1.2727... Remember: a repeating block of two digits goes over 99.
Why each option is right or wrong
- (a) 13/11 = 1.1818...
- (b) Right: 14/11 = 1.2727...
- (c) 127/99 = 1.2828...
- (d) 137/99 = 1.3838...
Answer: UPSC’s key. Explanation: written by UPSC Grade, not by UPSC.
Source: UPSC, Civil Services (Preliminary) Examination 2020, General Studies Paper II (CSAT), Series A. The paper on upsc.gov.in.