Correct Answer - Option 2 : 8060

**Given**

(x - 1/x) = 20

**Formula used**

(a - b)^{3} = a^{3} - b^{3} - 3ab × (a - b)

**Calculation**

(x - 1/x)^{3} = x^{3} - 1/x^{3} - 3(x)(1/x)(x - 1/x)

⇒ 20^{3} = x^{3} - 1/x^{3} - 3(20)

⇒ x^{3} - 1/x^{3} = 8060

**∴ x**^{3} - 1/x^{3} = 8060