It is currently 21 Sep 2017, 09:06

Happening Now:

Live Chat with Amy Mitson, Sr. Associate Director of Admissions at Tuck Dartmouth


Close

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

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 GMAT 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.

Close

Request Expert Reply

Confirm Cancel

Events & Promotions

Events & Promotions in June
Open Detailed Calendar

In an electric circuit, two resistors with resistances x and

  new topic post reply Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
TAGS:

Hide Tags

Expert Post
Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 41660

Kudos [?]: 124306 [0], given: 12077

Re: In an electric circuit, two resistors with resistances x and [#permalink]

Show Tags

New post 04 Sep 2017, 03:27
Shiv2016 wrote:
Bunuel

Why are we not considering r= x+y as it is mentioned that r is the combined resistance? Is it because we don't know how they are connected.


The question clearly gives the relationship between r, x, and y and it is NOT r = x + y: the reciprocal of r is equal to the sum of the reciprocals of x and y.
_________________

New to the Math Forum?
Please read this: Ultimate GMAT Quantitative Megathread | All You Need for Quant | PLEASE READ AND FOLLOW: 12 Rules for Posting!!!

Resources:
GMAT Math Book | Triangles | Polygons | Coordinate Geometry | Factorials | Circles | Number Theory | Remainders; 8. Overlapping Sets | PDF of Math Book; 10. Remainders | GMAT Prep Software Analysis | SEVEN SAMURAI OF 2012 (BEST DISCUSSIONS) | Tricky questions from previous years.

Collection of Questions:
PS: 1. Tough and Tricky questions; 2. Hard questions; 3. Hard questions part 2; 4. Standard deviation; 5. Tough Problem Solving Questions With Solutions; 6. Probability and Combinations Questions With Solutions; 7 Tough and tricky exponents and roots questions; 8 12 Easy Pieces (or not?); 9 Bakers' Dozen; 10 Algebra set. ,11 Mixed Questions, 12 Fresh Meat

DS: 1. DS tough questions; 2. DS tough questions part 2; 3. DS tough questions part 3; 4. DS Standard deviation; 5. Inequalities; 6. 700+ GMAT Data Sufficiency Questions With Explanations; 7 Tough and tricky exponents and roots questions; 8 The Discreet Charm of the DS; 9 Devil's Dozen!!!; 10 Number Properties set., 11 New DS set.


What are GMAT Club Tests?
Extra-hard Quant Tests with Brilliant Analytics

Kudos [?]: 124306 [0], given: 12077

Senior Manager
Senior Manager
User avatar
S
Joined: 29 Jun 2017
Posts: 305

Kudos [?]: 52 [0], given: 61

WE: Engineering (Transportation)
GMAT ToolKit User Reviews Badge
Re: In an electric circuit, two resistors with resistances x and [#permalink]

Show Tags

New post 04 Sep 2017, 03:35
Ans is simply D

kind of physics problem
R1 is first resistance R2 is another
if they are in series then R equivalent is R1+R2

if they are in parallel R equivalent is R1R2/(R1+R2)
so r1=x and r2=y therefore , xy/(x+y) is the answer... Ans is D



Also by what is given in ques

1/r = 1/x + 1/y
r = xy/ (x+y)

hence D
_________________

Give Kudos for correct answer and/or if you like the solution.

Kudos [?]: 52 [0], given: 61

Re: In an electric circuit, two resistors with resistances x and   [#permalink] 04 Sep 2017, 03:35

Go to page   Previous    1   2   [ 22 posts ] 

    Similar topics Author Replies Last post
Similar
Topics:
2 In a circuit board factory, all circuit boards that pass BabySmurf 2 15 Jun 2016, 16:25
2 EXPERTS_POSTS_IN_THIS_TOPIC Of the two-hundred electricians who joined the Jefferson City electric Bunuel 3 29 Dec 2016, 11:22
6 EXPERTS_POSTS_IN_THIS_TOPIC A box contains 20 electric bulbs, out of which 4 are defective. Two vaibhav123 5 28 Aug 2017, 23:01
3 EXPERTS_POSTS_IN_THIS_TOPIC If two resistors, A(R1) and B(R2) stand in parallel with each other in MathRevolution 3 14 Jan 2016, 18:54
7 EXPERTS_POSTS_IN_THIS_TOPIC In an electric circuit, two resistors with resistances x and y are droopy57 9 24 Apr 2016, 03:36
Display posts from previous: Sort by

In an electric circuit, two resistors with resistances x and

  new topic post reply Question banks Downloads My Bookmarks Reviews Important topics  


GMAT Club MBA Forum Home| About| Terms and Conditions| GMAT Club Rules| Contact| Sitemap

Powered by phpBB © phpBB Group | Emoji artwork provided by EmojiOne

Kindly note that the GMAT® test is a registered trademark of the Graduate Management Admission Council®, and this site has neither been reviewed nor endorsed by GMAC®.