- \(\frac{1}{2}\)
- 2
- 20
- NOT

Option 1 : \(\frac{1}{2}\)

**GIVEN:**

a = 11 and b = 9

**FORMULA USED:**

** **(a^{3} - b^{3}) = (a - b) (a^{2} + ab + b^{2})

**CALCULATION:**

(a^{2} + b^{2} + ab)/(a^{3} - b^{3}) = 1/(a - b)

⇒ 1/(11 - 9) = 1/2

∴ **a ^{2} + b^{2} + ab/a^{3}- b^{3} = 1/2**

India’s **#1 Learning** Platform

Start Complete Exam Preparation

Daily Live MasterClasses

Practice Question Bank

Mock Tests & Quizzes

Trusted by 2,17,83,996+ Students

Testbook Edu Solutions Pvt. Ltd.

1st & 2nd Floor, Zion Building,

Plot No. 273, Sector 10, Kharghar,

Navi Mumbai - 410210

[email protected]
Plot No. 273, Sector 10, Kharghar,

Navi Mumbai - 410210

Toll Free:1800 833 0800

Office Hours: 10 AM to 7 PM (all 7 days)