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

 It is currently 15 Oct 2019, 00:28

### 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

# A& B on working together take n hours to complete work.

Author Message
TAGS:

### Hide Tags

Director
Joined: 18 Feb 2019
Posts: 580
Location: India
GMAT 1: 460 Q42 V13
GPA: 3.6
A& B on working together take n hours to complete work.  [#permalink]

### Show Tags

04 Mar 2019, 10:55
5
00:00

Difficulty:

55% (hard)

Question Stats:

54% (01:33) correct 46% (01:58) wrong based on 52 sessions

### HideShow timer Statistics

A& B on working together take n hours to complete work. If B takes (n+9) hours to complete the work alone, how many hours will A take to complete the work alone?

I. A takes 5 hours less than B, to complete the work alone.
II. n=6
NUS School Moderator
Joined: 18 Jul 2018
Posts: 1025
Location: India
Concentration: Finance, Marketing
WE: Engineering (Energy and Utilities)
Re: A& B on working together take n hours to complete work.  [#permalink]

### Show Tags

04 Mar 2019, 11:08
1
Given that $$\frac{1}{A}+\frac{1}{B} = \frac{1}{n}$$
Also, $$\frac{1}{B} = \frac{1}{n+9}$$

From S1:

A takes 5 hours less, means A takes n+4 hours.
From the given info, $$\frac{1}{n+4}+\frac{1}{n+9} = \frac{1}{n}$$
Solving gives, n = 6.
Sufficient.

From S2:

Given n = 6. then A takes n+4 = 10 hours.
Sufficient.

Similar question to practice.

https://gmatclub.com/forum/machines-a-and-b-working-together-take-t-minutes-to-comple-147714.html
_________________
Press +1 Kudos If my post helps!
Re: A& B on working together take n hours to complete work.   [#permalink] 04 Mar 2019, 11:08
Display posts from previous: Sort by