SSC CGL 30 Aug 2015 Paper

© examsiri.com

Question : 106 of 200

Marks: +1, -0

If x =

{a-b}/{a+b}

, y =

{b-c}/{b+c}

, z =

{c-a}/{c+a}

, then

{(1-x)(1-y)(1-z)}/{(1+x)(1+y)(1+z)}

is equal to

1
0
2
$1/2$

Solution:

x/1

=

{a-b}/{a+b}

By componendo and dividendo,

{1-x}/{1+x}

=

{1-{a-b}/{a+b}}/{1+{a-b}/{a+b}}

=

{a+b-a+b}/{a+b+a-b}

=

b/a

Similarly,

{1-y}/{1+y}

=

c/b

;

{1-z}/{1+z}

=

a/c

∴ Expression =

{(1-x)(1-y)(1-z)}/{(1+x)(1+y)(1+z)}

=

b/a× c/b× a/c

= 1

© examsiri.com

Go to Question:

Prev Question

Next Question