GRE Prep Club Daily Prep
Thank you for using the timer - this advanced tool can estimate your performance and suggest more practice questions. We have subscribed you to Daily Prep Questions via email.
Customized
for You
Track
Your Progress
Practice
Pays
Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here.
help me figure out the question
[#permalink]
22 Oct 2016, 12:18
22 Oct 2016, 12:18
3
Bookmarks
00:00
Question Stats:
75% (01:14) correct
25% (00:20) wrong based on 4 sessions
Hide Show timer Statistics
Hi ,
X and Y are positive number and X is inversely proportional to Y. By what percent would the value of Y decrease , if the value of X is increases by 50%.
i followed as follows ,
since, xy = k and x increases by 50%,
y dereases by 50%
But, the answer is 33.33%.
what am i missing?
thank you
siva
X and Y are positive number and X is inversely proportional to Y. By what percent would the value of Y decrease , if the value of X is increases by 50%.
i followed as follows ,
since, xy = k and x increases by 50%,
y dereases by 50%
But, the answer is 33.33%.
what am i missing?
thank you
siva
Re: help me figure out the question
[#permalink]
23 Oct 2016, 00:55
23 Oct 2016, 00:55
2
Expert Reply
ssiva wrote:
Hi ,
X and Y are positive number and X is inversely proportional to Y. By what percent would the value of Y decrease , if the value of X is increases by 50%.
i followed as follows ,
since, xy = k and x increases by 50%,
y dereases by 50%
But, the answer is 33.33%.
what am i missing?
thank you
siva
X and Y are positive number and X is inversely proportional to Y. By what percent would the value of Y decrease , if the value of X is increases by 50%.
i followed as follows ,
since, xy = k and x increases by 50%,
y dereases by 50%
But, the answer is 33.33%.
what am i missing?
thank you
siva
Hi ssiva,
As you have rightly pointed out...
\(XY=k\) where k is a constant.
Now let X be increased by 0.5 or 50% and y be reduced by g%..
\((X+0.5X)(Y - \frac{g}{100}Y)=k\).
\(1.5X*Y(1 - \frac{g}{100})=k\).
Substituting values of k as XY from the first equation
\(1.5(1-\frac{g}{100})=1\)
or \((1-\frac{g}{100})=\frac{2}{3}\)
or \(1-\frac{g}{100}=\frac{2}{3}\)
or \(\frac{g}{100}=1-\frac{2}{3}\)
or \(\frac{g}{100}=\frac{1}{3}\)
Hence g= 33.3333.
Re: help me figure out the question
[#permalink]
23 Oct 2016, 01:49
23 Oct 2016, 01:49
sandy wrote:
ssiva wrote:
Hi ,
X and Y are positive number and X is inversely proportional to Y. By what percent would the value of Y decrease , if the value of X is increases by 50%.
i followed as follows ,
since, xy = k and x increases by 50%,
y dereases by 50%
But, the answer is 33.33%.
what am i missing?
thank you
siva
X and Y are positive number and X is inversely proportional to Y. By what percent would the value of Y decrease , if the value of X is increases by 50%.
i followed as follows ,
since, xy = k and x increases by 50%,
y dereases by 50%
But, the answer is 33.33%.
what am i missing?
thank you
siva
Hi ssiva,
As you have rightly pointed out...
\(XY=k\) where k is a constant.
Now let X be increased by 0.5 or 50% and y be reduced by g%..
\((X+0.5X)(Y - \frac{g}{100}Y)=k\).
\(1.5X*Y(1 - \frac{g}{100})=k\).
Substituting values of k as XY from the first equation
\(1.5(1-\frac{g}{100})=1\)
or \((1-\frac{g}{100})=\frac{2}{3}\)
or \(1-\frac{g}{100}=\frac{2}{3}\)
or \(\frac{g}{100}=1-\frac{2}{3}\)
or \(\frac{g}{100}=\frac{1}{3}\)
Hence g= 33.3333.
hi sandy,
thanks for writing.
your explanation was good. but, in case, x and y are directly proportion(x/y = K). i should replace - for + in
(Y - g/100*Y). shouldn't i?
