SSC Selection Post 2024 PYQ — Question 72

The correct answer is Option 4 i.e. 322.

$x^3+ {{1} \over x^3}$ = ($x+ {{1} \over x}$)³ - 3($x+ {{1} \over x}$)

⇒ $x^3+ {{1} \over x^3}$ = 7³ - 3 × 7 

⇒ 343 - 21 = 322