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Home›UPSC Prelims›Paper 2: General Studies II (CSAT)›Civil Services Aptitude Test (CSAT)›Basic Numeracy & Data Interpretation›The recurring decimal representation 1.272727... is equivalent to

The recurring decimal representation 1.272727... is equivalent to which one of the following?

20203Mprelimsupscyear-2020p2quantitative-aptitude
A.(a) 13/11
B.(b) 14/11Correct
C.(c) 127/99
D.(d) 137/99
Explanation & Solution

Correct Answer: (B) 14/11

Let x=1.272727...x = 1.272727...x=1.272727.... Multiplying by 100 gives 100x=127.272727...100x = 127.272727...100x=127.272727.... Subtracting the first equation from the second yields 99x=12699x = 12699x=126, so x=12699x = 12699\frac{126}{99}99126​x=99126​. Dividing both numerator and denominator by their greatest common divisor 9 gives x=1411x = 1411\frac{14}{11}1114​x=1114​.

हिंदी में प्रश्न एवं आदर्श उत्तर

आवर्त दशमलव निरूपण 1.272727... किसके समान है?

A.(a) 13/11
B.(b) 14/11सही
C.(c) 127/99
D.(d) 137/99

सही उत्तर: (B) 14/11

माना x=1.272727...x = 1.272727...x=1.272727..., तो 100x=127.272727...100x = 127.272727...100x=127.272727...। दोनों को घटाने पर 99x=126  ⟹  x=1269999x = 126   ⟹  \implies⟹ x = 12699\frac{126}{99}99126​99x=126⟹x=99126​ प्राप्त होता है। अंश और हर को 9 से विभाजित करने पर सरल भिन्न 14111411\frac{14}{11}1114​1114​ प्राप्त होती है।

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