SSC CGL 2022 PYQ — Question 74

SSC CGL - 05 Dec 2022 - Shift 4 • Quantitative Aptitude • Q74

If x2+y2+z2=xy+yz+zxx^2+y^2+z^2=xy+yz+zx and x = 1, then find the value of 10x4+5y4+7z413x2y2+6y2z2+3z2x2\frac{10x^4+5y^4+7z^4}{13x^2y^2+6y^2z^2+3z^2x^2}

Show answer & explanation

Correct answer: D

Explanation

The correct answer is option 4 i.e. 1.

We have been given 

x2+y2+z2=xy+yz+zxx^2+y^2+z^2=xy+yz+zx.........(1)

x = 1

Put y = 1 and z = 1 in equation 1.

⇒ 12 + 12 + 12  = 1 + 1 + 1

⇒ 3 = 3

The equation is satisfied;

So, the value of 10x4+5y4+7z413x2y2+6y2z2+3z2x2\frac{10x^4+5y^4+7z^4}{13x^2y^2+6y^2z^2+3z^2x^2}

⇒ (10 + 5 + 7)/(13 + 6 + 3) = 22/22 = 1