SSC CHSL 2022 PYQ — Question 59

SSC CHSL - 30 May 2022 - Shift 1 • Quantitative Aptitude • Q59

If 8x3 + 27y3 + 64z3 = 72 xyz, then the relation between x, y and z can be:

Show answer & explanation

Correct answer: A

Explanation

The correct answer is option 1 i.e. 2x + 3y = −4z

Concept used:

If x3 + y3 + z3 = 3xyz then

x + y + z = 0

Calculations:

⇒ 8x3 + 27y3 + 64z3 = 72 xyz

Using the above concept;

⇒ (2x)3 + (3y)3 + (4z)3 = 3 × (2x)(3y)(4z)

Hence, 2x + 3y + 4z = 0

Therefore, 2x + 3y = -4z