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SSC Selection Post 2022 PYQ — Question 69

SSC Selection Post - Higher Secondary Level - 01 Aug 2022 - Shift 3 • Quantitative Aptitude • Q69

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If the sum of two numbers is 126 and their HCF and LCM are 7 and 180, respectively, then the sum of the reciprocals of the two numbers is:

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Correct answer: C

Explanation

The correct answer is option 3 i.e.1101\over10.

Let numbers be 7a and 7b

7a + 7b = 126

⇒ a + b = 18

LCM = 7 × a × b = 180

⇒ a × b = 180/7

Sum of reciprocals = (1/7a) + (1/7b) = (a + b)/(7ab)

= 18/(7 × 180/7)

= 18/180

= 1/10