SSC CGL 2018 PYQ — Question 92

SSC CGL Tier II Quant - 09/03/2018 • Quantitative Aptitude • Q92

In a triangle ABC, AB = 12, BC = 18 and AC = 15. The medians AX and BY intersect sides BC and AC at X and Y respectively. If AX and BX intersect each other at O, then what is the value of √2 × OX?

Show answer & explanation

Correct answer: D

Explanation

The correct answer is Option 4 i.e. √23.

Length of median AX

⇒ 1/2 × √[2 × (AB2 + AC2) – BC2]

⇒ 1/2 × √[2 × (122 + 152) – 182]

⇒ 1/2 × √[2 × 369 – 324]

⇒ 1/2 × √414

⇒ 3/√2 × √23

We know that O is the centroid of the triangle and it divides the median in the ratio 2 : 1

Hence,

OX = 1/3 × AX = 1/3 × 3/√2 × √23 = √23/√2

Value of √2 × OX = √2 × √23/√2 = √23