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
we will pick new questions that match your level based on your Timer History
Track Your Progress
every week, we’ll send you an estimated GRE score based on your performance
Practice Pays
we will pick new questions that match your level based on your Timer History
Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here.
Thank you for using the timer!
We noticed you are actually not timing your practice. Click the START button first next time you use the timer.
There are many benefits to timing your practice, including:
Your score will improve and your results will be more realistic
Is there something wrong with our timer?Let us know!
Average of P and its reciprocal
[#permalink]
Updated on: 25 Jun 2019, 16:34
00:00
Question Stats:
74% (00:49) correct
25% (00:48) wrong based on 83 sessions
HideShow
timer Statistics
\(0<P<1\) where P is a fraction.
Quantity A
Quantity B
Average of P and its reciprocal
1
A) Quantity A is greater. B) Quantity B is greater. C) The two quantities are equal. D) The relationship cannot be determined from the information given.
I already know by substituting the values we can get the answer. I want someone to solve this question using Algebra and not substitution.
Average of P and its reciprocal
[#permalink]
25 Jun 2019, 05:43
4
skjoshi267 wrote:
\(0<P<1\) where P is a fraction.
Quantity A
Quantity B
Average of P and its reciprocal
1
Average of P and its reciprocal = \(\frac{\frac{1}{P} + P}{2}\)
\(=\frac{\frac{1 + P^2}{P}}{\frac{2}{1}}\)
\(=\frac{1+P^2}{2P}\)
So, we have: QUANTITY A: \(\frac{1+P^2}{2P}\)
QUANTITY B: \(1\)
We can complete this solution using matching operations
Since \(2P\) is POSITIVE, we can safely multiply both quantities by \(2P\) to get: QUANTITY A: \(1+P^2\) QUANTITY B: \(2P\)
If you notice that we have a PERFECT SQUARE hiding among the two quantities, then we can first subtract \(2P\) from both quantities to get: QUANTITY A: \(1+P^2-2P\) QUANTITY B: \(0\)
Rearrange to get: QUANTITY A: \(P^2-2P+1\) QUANTITY B: \(0\)
Factor to get: QUANTITY A: \((P-1)^2\) QUANTITY B: \(0\)
Since we know that P-1 does not equal 0, we know that \((P-1)^2\) is POSITIVE
Re: Average of P and its reciprocal
[#permalink]
10 Mar 2020, 00:19
1
Since we know 0<p<1 can't we just take numbers in p/q form?
For example if p=1/2 then A is basically stating 1/2+2 / 2= 5/4. Similarly if we take other fractions the result will be A>B. For eg if we take 1/4+4/1=> 17/8.