SSC CHSL 2020 PYQ — Question 52

SSC CHSL - 19th October 2020 - Shift 3 • Quantitative Aptitude • Q52

If x3 - 6x2 + ax + b is divisible by (x2 - 3x + 2), then the values of a and b are:

Show answer & explanation

Correct answer: C

Explanation

The correct answer is Option 3 i.e a = 11 and b = -6.

Understanding/Application

x3 - 6x2 + ax + b is divisible by (x2 - 3x + 2)

Let the quotient be x - p

(x2 - 3x + 2) (x - p) = x3 - 6x2 + ax + b

x3 - 3x2 + 2x - px2 + 3px - 2p = x3 - 6x2 + ax + b

x3 - (3 + p)x2 + (2 + 3p)x - 2p = x3 - 6x2 + ax + b

Comparing both sides -

-(3 + p) = - 6

p = 3

2 + 3p = a

a = 11

-2p = b

b = -6