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

 It is currently 16 Oct 2019, 17:30

### 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

# One man started a project on the first day. One man joins on each day

Author Message
TAGS:

### Hide Tags

Manager
Joined: 13 Jun 2012
Posts: 199
Location: United States
WE: Supply Chain Management (Computer Hardware)
One man started a project on the first day. One man joins on each day  [#permalink]

### Show Tags

30 Oct 2018, 06:06
5
00:00

Difficulty:

55% (hard)

Question Stats:

59% (02:11) correct 41% (02:21) wrong based on 49 sessions

### HideShow timer Statistics

One man started a project on the first day. One man joins on each day starting from the second day. The project will be completed in exactly 20 days. Instead, if a team of 7 men work regularly, the work will be completed exactly in n days. What is n?

a.15
b.20
c.24
d.30
e.35
Senior Manager
Joined: 09 Jun 2014
Posts: 352
Location: India
Concentration: General Management, Operations
Re: One man started a project on the first day. One man joins on each day  [#permalink]

### Show Tags

30 Oct 2018, 06:38
Turkish wrote:
One man started a project on the first day. One man joins on each day starting from the second day. The project will be completed in exactly 20 days. Instead, if a team of 7 men work regularly, the work will be completed exactly in n days. What is n?

a.15
b.20
c.24
d.30
e.35

So,one man joins on day till the 20th day implies

1+2+3+4....20 =1 MANDAY + 2 MANDAYS+3 MANDAYS ...20 MANDAYS

= Arithmetic progression(formula) = (N(N+1))/2= 20*21/2= 210

So 210 is the total amount of work.(units of work)

Now
team of 7 men work regularly, the work will be completed exactly in n days.
this means total amount of work done by these 7 men team= 7*n = 7n units of work

Now 210 = 7n
n= 30

So OA D

Press Kudos if it helps!!
Re: One man started a project on the first day. One man joins on each day   [#permalink] 30 Oct 2018, 06:38
Display posts from previous: Sort by