NDA 2016 Maths · Mathematics · Quadratic Equations · medium

If the roots of x^2-5x+k=0 are in the ratio 2:3, then k is equal to

Single correct option

If the roots of

x^2-5x+k=0

are in the ratio

2:3

, then

k

is equal to

Show answer and solution

Answer: (D) $6$

Let the roots be

2m

and

3m

. The sum is

5m=5

, so

m=1

and the roots are

2

and

3

. The product of roots is

k=2\times3=6

. Using

k=5

comes from reading the sum as the product, and 15 comes from multiplying the wrong pair.

Original question written in the NDA 2016 Maths pattern and checked twice for the correct answer. Not an official question paper. How we write and check questions · Corrections policy · Report a mistake