GMAT Question of the Day - Daily to your Mailbox; hard ones only

It is currently 13 Oct 2019, 21:37

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

Two numbers have a sum of 10 and a product of 20. What is the sum of t

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

Hide Tags

Find Similar Topics 
Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 58335
Two numbers have a sum of 10 and a product of 20. What is the sum of t  [#permalink]

Show Tags

New post 13 Sep 2017, 01:45
00:00
A
B
C
D
E

Difficulty:

  35% (medium)

Question Stats:

75% (01:42) correct 25% (02:11) wrong based on 56 sessions

HideShow timer Statistics

Current Student
User avatar
P
Joined: 02 Jul 2017
Posts: 292
Concentration: Entrepreneurship, Technology
GMAT 1: 730 Q50 V38
GMAT ToolKit User
Re: Two numbers have a sum of 10 and a product of 20. What is the sum of t  [#permalink]

Show Tags

New post 13 Sep 2017, 03:18
Let 2 numbers be a and b.
Given: a+b =10 and a*b =20

Find : \(\frac{1}{a} + \frac{1}{b}\)

as a+b=10 and ab =20

=>\(\frac{a+b}{ab} =\frac{10}{20}\)

=>\(\frac{a}{ab} + \frac{b}{ab} =\frac{1}{2}\)

=>\(\frac{1}{b} +\frac{1}{a} = \frac{1}{2}\) = Answer

Answer : D
Intern
Intern
User avatar
Joined: 13 Sep 2017
Posts: 1
Re: Two numbers have a sum of 10 and a product of 20. What is the sum of t  [#permalink]

Show Tags

New post 13 Sep 2017, 03:19
The two numbers are 5+sqroot(5) and 5-sqroot(5) solving the reciprocals of the two numbers the answer is 1/2.


Sent from my iPhone using GMAT Club Forum mobile app
Senior SC Moderator
avatar
V
Joined: 22 May 2016
Posts: 3536
Two numbers have a sum of 10 and a product of 20. What is the sum of t  [#permalink]

Show Tags

New post 13 Sep 2017, 03:22
1
1
Bunuel wrote:
Two numbers have a sum of 10 and a product of 20. What is the sum of the reciprocals of the two numbers?

A. 1/10
B. 1/8
C. 1/4
D. 1/2
E. 2

x + y = 10
xy = 20

What is the sum of the reciprocals of the two numbers?

\(\frac{1}{x}\) + \(\frac{1}{y}\) = \(\frac{(x + y)}{xy}\)

Substituting values from above for (x + y) and (xy):

\(\frac{10}{20}\) = \(\frac{1}{2}\)

Answer

_________________
SC Butler has resumed! Get two SC questions to practice, whose links you can find by date, here.




Choose life.
Non-Human User
User avatar
Joined: 09 Sep 2013
Posts: 13081
Re: Two numbers have a sum of 10 and a product of 20. What is the sum of t  [#permalink]

Show Tags

New post 07 Feb 2019, 18:57
Hello from the GMAT Club BumpBot!

Thanks to another GMAT Club member, I have just discovered this valuable topic, yet it had no discussion for over a year. I am now bumping it up - doing my job. I think you may find it valuable (esp those replies with Kudos).

Want to see all other topics I dig out? Follow me (click follow button on profile). You will receive a summary of all topics I bump in your profile area as well as via email.
_________________
GMAT Club Bot
Re: Two numbers have a sum of 10 and a product of 20. What is the sum of t   [#permalink] 07 Feb 2019, 18:57
Display posts from previous: Sort by

Two numbers have a sum of 10 and a product of 20. What is the sum of t

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





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