SSC CGL 2023 PYQ — Question 58

The correct answer is Option 1 i.e. $2\frac{21}{25}$.

⇒ $(5y+\frac{5}{y})=11$

⇒ $5(y+\frac{1}{y})=11$

⇒ $(y+\frac{1}{y})={11\over5}$

Squaring both sides

⇒ $(y+\frac{1}{y})^2=({11\over5})^2$

⇒ $y^2+(\frac{1}{y})^2 + 2{ \times y \times {1\over y}}={121\over25}$

⇒ $y^2+\frac{1}{y^2} + 2={121\over25}$

⇒​​​​​​​ $y^2+\frac{1}{y^2} ={121\over25} - 2$

⇒​​​​​​​ $y^2+\frac{1}{y^2} ={121 - 50\over25}$

⇒​​​​​​​ $y^2+\frac{1}{y^2} ={71\over25}$ 

⇒​​​​​​​​​​​​​​ $y^2+\frac{1}{y^2}$ = $2\frac{21}{25}$