SSC CGL 2022 PYQ — Question 38

SSC CGL Tier II - Quant - 3 Feb 2022 • Quantitative Aptitude • Q38

If 27x3 - 64 y3 = (Ax + By) (Cx2 - Dy2 + 12xy), then the value of 4A + B + 3C + 2D is: 

Show answer & explanation

Correct answer: B

Explanation

The correct answer is option 2 i.e. 3.

27x3 - 64 y3 = (Ax + By) (Cx2 - Dy2 + 12xy)

(3x)3 - (4y)3 = (3x - 4y)(9x2 + 16y2 + 12xy)

(3x - 4y)(9x2 + 16y2 + 12xy) = (Ax + By) (Cx2 - Dy2 + 12xy)

On comparing we get,

A = 3 , B = -4 , C = 9 and D = -16.

4A + B + 3C + 2D 

= 4 × 3 - 4 + 3 × 9 + 2 × -16

= 12 - 4 + 27 - 32

= 3.