any expert plz help?

I think the answer is D - each by itself sufficient. Do you have the Original answer ?

no u r wrong plz explian yr answers

pradeepkaushal9518 wrote:no u r wrong plz explian yr answers

Double check your answer!!! Its an Official Guide question.


Let price of X be x and that of Y be y
new X = 1.1x and new Y= .9y

We have to find .9y/x or .9(y/x)

1) 1.1x=y
y/x=1.1

Sufficient

2).1x=10/11* .1y

y/x = 11/10 =1.1

Sufficient

With DS problems, I always ask myself the following three questions:

What do I want?
What do I have?
What do I need?

The goal is not to solve but only to determine whether the statement gives you sufficient information to solve. In other words: Is the statement giving me what I need?

In this case:

What do I want? What is the question asking for?

The question is asking for the relationship -- in other words, the ratio -- between the reduced price of stock Y and the original price of stock X.
Let's say x = the original price of stock X and y = the original price of stock Y.
Stock Y is being reduced by .1y, so the reduced price is y - .1y = .9y.

So (Reduced Y)/(Original X) = (.9y)/x. This is what I want.

What do I have? Before I look at the two statements, what information have I been given?

Stock X is being increased by .1x, so increased X = x + .1x = 1.1x.
Stock Y is being decreased by .1y, so reduced Y = .9y.

What do I need? What's the missing information that I need in order to answer the question?

Since (.9y)/x = .9 * (y/x), what I need is the value of y/x.

Statement 1:

Increased X = Original Y.

1.1x = y

So y/x = 1.1. SUFFICIENT.

Statement 2:

Increase in stock X = .1x.
Decrease in stock Y = .1y.

Statement 2 says:

.1x = (10/11)(.1y)

So dividing each side by .1y we get:

(.1x)/(.1y) = 10/11

So x/y = 10/11, y/x = 11/10 = 1.1. SUFFICIENT.

The correct answer is D.

IMO D

price of X= x
price of Y= y
X = 1.1x
Y= .9y

Q is .9(y/x) ?

1) 1.1x=y
y/x=1.1

Sufficient

2).1x=10/11* .1y

y/x = 11/10 =1.1

Sufficient