by: Bunuel
21 mins
by: Bunuel
21 mins
Events & Promotions
|
|
GMAT 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.
Sep 2107:00 PM EDT
-10:00 PM EDT
Boost your GMAT score in less than one month in a live online class + 6 months access to TTP OnDemand video courses included!
Be sure to select an answer first to save it in the Error Log before revealing the correct answer (OA)!
Difficulty:
5%
(low)
Question Stats:
89% (01:23) correct
11%
(02:09)
wrong
based on 224
sessions
History
Date
Time
Result
Not Attempted Yet
\(\sqrt{\frac{7}{5}} - \sqrt{\frac{5}{7}} = \)
(A) \(\frac{2}{\sqrt{35}}\)
(B) \(\sqrt{25}\)
(C) \(\frac{5}{\sqrt{35}}\)
(D) \(\frac{7}{\sqrt{35}}\)
(E) \(\sqrt{35}\)
_________________
(A) \(\frac{2}{\sqrt{35}}\)
(B) \(\sqrt{25}\)
(C) \(\frac{5}{\sqrt{35}}\)
(D) \(\frac{7}{\sqrt{35}}\)
(E) \(\sqrt{35}\)
_________________
New to the GMAT Club?
- • Questions: Question Bank | Bunuel's Signature Collection
• Tests: GMAT Club Tests | Forum Quiz
• Guides: Quantitative | Critical Reasoning | Reading Comprehension | Ultimate Quant Guide | All You Need for Quant
• Rules: Quantitative | Verbal
Posts: 281
\(\sqrt{\frac{7}{5}}-\sqrt{\frac{5}{7}}=\frac{\sqrt{7}}{\sqrt{5}}- \frac{\sqrt{5}}{\sqrt{7}}= \frac{\sqrt{7}*\sqrt{7}-\sqrt{5}*\sqrt{5}}{\sqrt{35}}=\frac{7-5}{\sqrt{35}}=\frac{2}{\sqrt{35}}\)
Answer: A
Answer: A
General Discussion
\(\sqrt{\frac{7}{5}} - \sqrt{\frac{5}{7}} = x\)
\(x^2 = \frac{7}{5} - 2\sqrt{1} + \frac{5}{7}\)
\(x^2 = \frac{74}{35} - 2\)
\(x^2 = \frac{4}{35}\)
\(x = \frac{2}{\sqrt{35}}\)
Answer A.
_________________
\(x^2 = \frac{7}{5} - 2\sqrt{1} + \frac{5}{7}\)
\(x^2 = \frac{74}{35} - 2\)
\(x^2 = \frac{4}{35}\)
\(x = \frac{2}{\sqrt{35}}\)
Answer A.
_________________
Starting out with GMAT Quant? All You Need for the GMAT Quantitative (Math) Section!
Filters for Targeted Practice
Advanced stage of your Quant Prep? Collection of Toughest Quant Questions
Filters for Targeted Practice
Advanced stage of your Quant Prep? Collection of Toughest Quant Questions
1. We are asked to find the difference between 2 irrational fractions.
2. To do this, it's best to make them have a common denominator.
3. \(\sqrt{\frac{7}{5}} - \sqrt{\frac{5}{7}} = \frac{\sqrt{7}}{\sqrt{5}} * \frac{\sqrt{7}}{\sqrt{7}} - \frac{\sqrt{5}}{\sqrt{7}} * \frac{\sqrt{5}}{\sqrt{5}} = \frac{7}{\sqrt{35}} - \frac{5}{\sqrt{35}} = \frac{2}{\sqrt{35}}\)
4. So, our answer is \(\frac{2}{\sqrt{35}}\).
2. To do this, it's best to make them have a common denominator.
3. \(\sqrt{\frac{7}{5}} - \sqrt{\frac{5}{7}} = \frac{\sqrt{7}}{\sqrt{5}} * \frac{\sqrt{7}}{\sqrt{7}} - \frac{\sqrt{5}}{\sqrt{7}} * \frac{\sqrt{5}}{\sqrt{5}} = \frac{7}{\sqrt{35}} - \frac{5}{\sqrt{35}} = \frac{2}{\sqrt{35}}\)
4. So, our answer is \(\frac{2}{\sqrt{35}}\).
Posts: 92
√(7/5)-√(5/7) = √((7*7)/(5*7)) -√((5*5)/(7*5)) = 7/(√35)- 5/(√35) = 2/(√35)
(7/5)^1/2-(5/7)^1/2
Taking LCM
[(7^1/2)*(7^1/2)-(5^1/2)*(5^1/2)]/(35^1/2)
(7-5)/(35^1/2)
2/(35^1/2)
ANSWER:A
Posted from my mobile device
Taking LCM
[(7^1/2)*(7^1/2)-(5^1/2)*(5^1/2)]/(35^1/2)
(7-5)/(35^1/2)
2/(35^1/2)
ANSWER:A
Posted from my mobile device
Posts: 145
√(7/5)-√(5/7) = √((7*7)/(5*7)) -√((5*5)/(7*5)) = 7/(√35)- 5/(√35) = 2/(√35)
Answer: A.
Answer: A.
Bunuel, I thought the GMAT would typically not allow an answer with a radical in the denominator and as such we have to rationalize when we see a radical in the denominator
Moderator:
Announcements
Monday, Sep 14, 2026
11:30am NY / 3:30pm London / 9pm Mumbai
Subscribe to GMAT Club for New Podcast Episodes, Debriefs, & Insightful Sessions on GMAT Preparation
Tuck at Dartmouth
AI at Dartmouth Tuck: How the School Is Preparing Leaders for the Age of Artificial Intelligence
Inside the courses, research, and hands-on learning defining wise, decisive leadership in an AI-driven world.
Read More
Inside the courses, research, and hands-on learning defining wise, decisive leadership in an AI-driven world.
Read More
Top 5 GMAT Debrief Videos
Success stories and strategies from high-scoring candidates.