Find all School-related info fast with the new School-Specific MBA Forum

 It is currently 01 Jul 2016, 01:28

### 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

# Events & Promotions

###### Events & Promotions in June
Open Detailed Calendar

# A person can dig a well in 5 hours. He invites 2 person who

Author Message
Intern
Joined: 07 Mar 2006
Posts: 4
Followers: 0

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

A person can dig a well in 5 hours. He invites 2 person who [#permalink]

### Show Tags

08 Mar 2006, 22:24
This topic is locked. If you want to discuss this question please re-post it in the respective forum.

A person can dig a well in 5 hours. He invites 2 person who can work 3/4 as fast and another 2 person who can work 1/5 as fast as he does. If the 5 person team digs the same well, how long will it take for the team to finsh the job ?
A) 1:20
B) 1:30
C) 1:40
D) 1:50
E) 2:10

Guys, can you please explain how to solve this problem ?
Director
Joined: 10 Oct 2005
Posts: 720
Followers: 3

Kudos [?]: 15 [0], given: 0

### Show Tags

09 Mar 2006, 05:28
vkgmat wrote:
A person can dig a well in 5 hours. He invites 2 person who can work 3/4 as fast and another 2 person who can work 1/5 as fast as he does. If the 5 person team digs the same well, how long will it take for the team to finsh the job ?
A) 1:20
B) 1:30
C) 1:40
D) 1:50
E) 2:10

Guys, can you please explain how to solve this problem ?

I dunno may be some typo? He invites 2 person who can work 3/4 as fast should we count them as 3/4 one and 3/4 second? or both together?
_________________

IE IMBA 2010

Senior Manager
Joined: 11 Nov 2005
Posts: 328
Location: London
Followers: 1

Kudos [?]: 11 [0], given: 0

### Show Tags

09 Mar 2006, 05:44
I get 1:45 ?

assuming each person's rate is 3/4 or 1/5
Intern
Joined: 17 Feb 2006
Posts: 11
Followers: 0

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

### Show Tags

09 Mar 2006, 12:22
vkgmat wrote:
A person can dig a well in 5 hours. He invites 2 person who can work 3/4 as fast and another 2 person who can work 1/5 as fast as he does. If the 5 person team digs the same well, how long will it take for the team to finsh the job ?
A) 1:20
B) 1:30
C) 1:40
D) 1:50
E) 2:10

Guys, can you please explain how to solve this problem ?

1st person can finish 1/5 of the digging in 1 hour
first 2 people can finish digging 2/(5/(3/4)) = 3/10 in 1 hour
second 2 people can finish digging in 2/(5/(1/5)) = 2/25 in 1 hour

Adding them via a common denominator we get up we get:

(1/T) = 10/50 + 15/50 + 4/50 = 29/50

Thus the time to dig the entire well, T is 50/29 = 1 and 21/29 of an hour

This is roughly equal to 1 hour and 40 minutes (21/29 =~ 40/60)

Manager
Joined: 14 Jun 2005
Posts: 100
Followers: 1

Kudos [?]: 9 [0], given: 0

### Show Tags

09 Mar 2006, 12:37
50/29 hours

duh....i was wondering why there were ratios in the answers...it was time!
Intern
Joined: 07 Mar 2006
Posts: 4
Followers: 0

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

### Show Tags

09 Mar 2006, 13:39
The OA is C (1:40)

Yurik79 : We should count 3/4 twice as explained by gpmagnus

hellom3p : The answer are not ratio they are time (1 Hour and 40 Min)
Director
Joined: 10 Oct 2005
Posts: 720
Followers: 3

Kudos [?]: 15 [0], given: 0

### Show Tags

09 Mar 2006, 21:51
I think that this question is not formulated correct. how long will it take for the team to finsh the job ? I think that the word approximately should be in the question stem IMHO[/u]
_________________

IE IMBA 2010

Manager
Joined: 20 Mar 2005
Posts: 201
Location: Colombia, South America
Followers: 1

Kudos [?]: 11 [0], given: 0

### Show Tags

09 Mar 2006, 23:16
same as gpmagnus

1 / (1/5 + 3/10 + 2/25) = 50/29

however i wasn't sure cause is close to 1:45
SVP
Joined: 14 Dec 2004
Posts: 1702
Followers: 2

Kudos [?]: 94 [0], given: 0

### Show Tags

10 Mar 2006, 00:18
"C"

1 hour ~43 mins.
Manager
Joined: 04 Jan 2006
Posts: 58
Followers: 1

Kudos [?]: 2 [0], given: 0

### Show Tags

10 Mar 2006, 08:53
Hello gpmagnus,
Can you explain how you got these lines

first 2 people can finish digging 2/(5/(3/4)) = 3/10 in 1 hour
second 2 people can finish digging in 2/(5/(1/5)) = 2/25 in 1 hour

from the qn(2 are 3/4 as fast and 2 are 1/5th as fast as the first person)
Display posts from previous: Sort by