prachich1987 wrote:What is the ratio of x to y?

(1) 5x = 2y

(2) 2y = 7x - 8

find x/y

st(1) x=2y/5 <=> x=(2/5)*y <=> x/y=2/5 Sufficient
st(2) (7x-8)/2y=1 <=> (7/2)*(x/y)-(8/2)*(1/y)=1 <=> (7/2)*(x/y)=(8+2y)/2y <=> (7/2)*(x/y)*2y ... endless translations Not sufficient

IOM A

What is the ratio of x to y?

(1) 5x = 2y

(2) 2y = 7x - 8


Rephrase the question : what is x/y?


Statement 1:

5x = 2y

x/y = 2/5 provided y not 0

since y not = 0 information is not there ==> Statement 1 is insufficient


Statement 2 :

2y = 7x - 8

=> x/y = 1/7 + 4/7y (provided y not = 0)

=> to get x/y we require y , hence Statement 2 is insufficient


Combining Statement 1 & 2

we solve 2 equations to get x = 4 & y = 10 to get x/y = 2/5

Answer is C

SUHAILK wrote:What is the ratio of x to y?

(1) 5x = 2y

(2) 2y = 7x - 8


Rephrase the question : what is x/y?


Statement 1:

5x = 2y

x/y = 2/5 provided y not 0

since y not = 0 information is not there ==> Statement 1 is insufficient

are not you making extra assumptions for this question? x can not be divided by y if y=0, hence 0 is canceled out inherently. We are asked to find the ratio and not to assess if the ratio exists

Experts plz reply

Night reader wrote:

SUHAILK wrote:What is the ratio of x to y?

(1) 5x = 2y

(2) 2y = 7x - 8


Rephrase the question : what is x/y?


Statement 1:

5x = 2y

x/y = 2/5 provided y not 0

since y not = 0 information is not there ==> Statement 1 is insufficient

are not you making extra assumptions for this question? x can not be divided by y if y=0, hence 0 is canceled out inherently. We are asked to find the ratio and not to assess if the ratio exists

I dont think this is a extra assumption. It is a basic rule for solving equation.

And to arrive at the ratio of x to y, it will be required to determine whether the ratio exists or not.

Lets wait for expert reply to get clarity from GMAT point of view.

the problem is tricky, and my answer is C
(1) 5x=2y is valid for x=y=0 with ratio x/y=0
or for x=2 and y=5, with ratio x/y=2/5
as we have no restrictions on the value of x and y 1 st insuff
(2) 2y=7x-8 insuff
both give us the ratio of x,y as x.y can`t be 0
from 1 st x=2/5*y. and
10y=14y-40
y=10, x=4. x/y=2/5

IMO A

we cant assume that X/Y can be 0

prachich1987 wrote:What is the ratio of x to y?

(1) 5x = 2y

(2) 2y = 7x - 8

I received a PM asking me to comment.

Since a ratio is sometimes written as a fraction, I can't imagine that the GMAT writers would suggest that statement 1 is insufficient because if x=y=0, then the ratio of x/y = 0/0. Division by 0 is not discussed on the GMAT. If this question were to appear on the GMAT, the information that x≠0 and y≠0 likely would be included.

It is important to recognize when a value can be equal to 0, however. Let's say that the question above said the following:

If x and y are nonnegative integers, is x<y?

When we examine statement 1, letting x=y=0 would not result in division by 0. Thus, statement 1 would be insufficient.