Practicing Success

Target Exam

CUET

Subject

General Test

Chapter

Quantitative Reasoning

Topic

Algebra

Question:

If $x + y + z = 10, xy + yz + zx =25$ and $xyz = 100$, then what is the value of $(x^3 + y^3 + z^3)?$

Options:

540

450

550

570

Correct Answer:

550

Explanation:

Given ,

x + y + z = 10

 xy + yz + zx = 25

xyz = 100

We know,

x3 + y3 + z3 – 3xyz = (x + y + z) [(x + y + z)2 – 3 (xy + yz + zx)]

x3 + y3 + z3 – 3 × 100 = 10 [102 – 3 × 25]

x3 + y3 + z3 – 300 = 10 (100 – 75) = 10 × 25 = 250

x3 + y3 + z3 = 250 + 300 = 550