SSC CGL 2019 PYQ — Question 43

SSC CGL Tier II - Quant 13th Sep. 19 • Quantitative Aptitude • Q43

A circle touches the side BC of triangle ABC at D & AB and AC is produced to E and F respectively to touch the circle. If AB = 10 cm, AC = 8.6 cm & BC = 6.4 cm then BE = ?

Show answer & explanation

Correct answer: D

Explanation

Note: The question has been modified since it was incorrect according to the answer key released by the SSC.

The correct answer is option 4 i.e 2.5 cm.

Given: AB = 10 cm, BC = 6.4 cm, AC = 8.6 cm

As the circle touches side BC at D, let BD = x, DC = y

BD + DC = 6.4 (Given in the question)

⇒ x + y = 6.4       --------------- eqn (1)

Then,

BE = x, CF = y (Lengths of tangents from the same point outside the circle are equal)

As AE touches the circle at point E and AF touches the circle at point F only:

AE = AF

⇒ AB + BE = AC + CE 

⇒ 10 + x = 8.6 + y

⇒ y - x = 1.4        -------------- eqn (2)

From eqn 1 and eqn 2, we get, 

x = 2.5 cm = BE