If x/y = 2.6, what is the value of (x - y)/(x + y)?

Question

If  \frac{x}{y} = 2.6 , what is the value of  \frac{x-y}{x+y} ?

A.  \frac{2}{7}

B.  \frac{3}{8}

C.  \frac{4}{9}

D.  \frac{5}{9}

E.  \frac{7}{10}

This is a  PS Butler Question

Check the links to other Butler Projects:

Data Sufficiency Butler  
  Critical Reasoning Butler

LucidGhost · Answer

x/y=2.6 =26/10 =13/5 
x=13k
y=5k 
x-y=13k-5k = 8k
x+y=13k+5k = 18k

Required fraction= 8k/18k =4/9

StoneWindow · Answer

Hi,
Just take y common from the numerator and denominator.

It should be like this: ((x/y) - 1) / ((x/y) + 1)

Now replace the value of x/y in the equation. You should get 4/9.

Parinpatel · Answer

Apply Componendo Dividendo 
x-y/x+y = a-b/a+b

Or you can also go by mathematical manipulations 
you would get 4/9 by both

Ninouchou · Answer

since x/y = 2.6 we know that x = 2.6y

so if we replace x by 2.6y in the expression (x−y)/(x+y)

we then have : (2.6y−y)/(2.6y+y) = 1.6y/3.6y = 4/9

Kevi · Answer

Could be rewritten as (x/y -1)/(x/y +1) 
=(2.6-1)/(2.6+1)
= 1.6/3.6 
=4/9

SwiftMonk · Answer

x/y - 1 = (x-y)/y =2.6-1 =1.6 .........(1)
x/y + 1=(x+y)/y = 2.6 +1+ 3.6 ........(2)

perform, eq. 1/2
(x-y)/(x+y) = 1.6/3.6 =4/9
option C is the winner.

TheAdmissionHub · Answer

Let's turn the decimal number into a fraction:  \frac{x}{y}=\frac{26}{10}=\frac{13}{5}  ⭢  x= \frac{13}{5}y

\frac{x-y}{x+y}=(\frac{13}{5}y-y)/(\frac{13}{5}y+y)=(\frac{13}{5}-1)/(\frac{13}{5}+1)=\frac{8}{5}/\frac{18}{5}=\frac{8}{5}*\frac{5}{18}=\frac{4}{9}

Answer: C

Prep Toolkit