SSC CGL 2019 PYQ — Question 35

SSC CGL Tier II - Quant 13th Sep. 19 • Quantitative Aptitude • Q35

Let x = 271/6−634{27}^{1/6} - {\sqrt{6 {3\over4}}} and y =45+605+24580+125{{\sqrt {45}} + {\sqrt {605}} +{\sqrt {245}}}\over {{\sqrt {80}}+ {\sqrt {125}}}, then the value of x² + y² is?

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Correct answer: D

Explanation

The correct answer is option 4 i.e. 223/36

x = 271/6−634{27}^{1/6} - {\sqrt{6 {3\over4}}}

= 3−274{\sqrt 3} - {\sqrt{27\over4}}

= 3−323{\sqrt 3} - {3\over2}{\sqrt{3}}

= −32- {{\sqrt{3}}}\over 2

x2 = 3/4

y = 45+605+24580+125{{\sqrt {45}} + {\sqrt {605}} +{\sqrt {245}}}\over {{\sqrt {80}}+ {\sqrt {125}}}

y = 35+115+7545+55{3{\sqrt {5}} + {11\sqrt {5}} +{7\sqrt {5}}}\over {{4\sqrt {5}}+ {5\sqrt {5}}}

y = 21595{21{\sqrt {5}}}\over {9\over5}

y2 = 2205/405 = 49/9

Now,  x2 + y2 = 3/4 + 49/9 = (196 + 27)/36 = 223/36