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

 It is currently 15 Oct 2019, 00:05 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

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.  If a + b = 7 and ab = 5, then what is the value of 1/a + 1/b?

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

Hide Tags

Math Expert V
Joined: 02 Sep 2009
Posts: 58339
If a + b = 7 and ab = 5, then what is the value of 1/a + 1/b?  [#permalink]

Show Tags 00:00

Difficulty:   15% (low)

Question Stats: 82% (00:51) correct 18% (01:40) wrong based on 22 sessions

HideShow timer Statistics

If a + b = 7 and ab = 5, then what is the value of 1/a + 1/b?

A. 5/12

B. 2/5

C. 12/5

D. 5/7

E. 7/5

_________________
Math Expert V
Joined: 02 Aug 2009
Posts: 7958
If a + b = 7 and ab = 5, then what is the value of 1/a + 1/b?  [#permalink]

Show Tags

2
1
Bunuel wrote:
If a + b = 7 and ab = 5, then what is the value of 1/a + 1/b?

A. 5/12

B. 2/5

C. 12/5

D. 5/7

E. 7/5

As a+b and ab are related to $$\frac{1}{a}+\frac{1}{b}$$ but the equations look different, so let us modify $$\frac{1}{a}+\frac{1}{b}$$..
$$\frac{1}{a}+\frac{1}{b}=\frac{(a+b)}{ab}=7/5$$

E
_________________
GMAT Club Legend  D
Joined: 18 Aug 2017
Posts: 4986
Location: India
Concentration: Sustainability, Marketing
GPA: 4
WE: Marketing (Energy and Utilities)
Re: If a + b = 7 and ab = 5, then what is the value of 1/a + 1/b?  [#permalink]

Show Tags

Bunuel wrote:
If a + b = 7 and ab = 5, then what is the value of 1/a + 1/b?

A. 5/12

B. 2/5

C. 12/5

D. 5/7

E. 7/5

1/a + 1/b
a+b/ab = 7/5
IMO E
Target Test Prep Representative D
Status: Founder & CEO
Affiliations: Target Test Prep
Joined: 14 Oct 2015
Posts: 8043
Location: United States (CA)
Re: If a + b = 7 and ab = 5, then what is the value of 1/a + 1/b?  [#permalink]

Show Tags

Bunuel wrote:
If a + b = 7 and ab = 5, then what is the value of 1/a + 1/b?

A. 5/12

B. 2/5

C. 12/5

D. 5/7

E. 7/5

Adding 1/a + 1/b, we have:

b/ab + a/ab = (b + a)/ab = 7/5.

_________________

Scott Woodbury-Stewart

Founder and CEO

Scott@TargetTestPrep.com

See why Target Test Prep is the top rated GMAT quant course on GMAT Club. Read Our Reviews

If you find one of my posts helpful, please take a moment to click on the "Kudos" button. Re: If a + b = 7 and ab = 5, then what is the value of 1/a + 1/b?   [#permalink] 10 Mar 2019, 19:53
Display posts from previous: Sort by

If a + b = 7 and ab = 5, then what is the value of 1/a + 1/b?

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

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