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

 It is currently 28 Jun 2016, 14:14

### 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

# Had to guess on this one since time was running and I was

Author Message
Director
Joined: 08 Jun 2007
Posts: 583
Followers: 2

Kudos [?]: 87 [0], given: 0

Had to guess on this one since time was running and I was [#permalink]

### Show Tags

11 Sep 2007, 20:19
00:00

Difficulty:

(N/A)

Question Stats:

0% (00:00) correct 0% (00:00) wrong based on 0 sessions

### HideShow timer Statistics

This topic is locked. If you want to discuss this question please re-post it in the respective forum.

Had to guess on this one since time was running and I was wasting my time solving this.
Some easy steps?
Attachments

11.gif [ 16.82 KiB | Viewed 613 times ]

Director
Joined: 17 Sep 2005
Posts: 924
Followers: 3

Kudos [?]: 60 [0], given: 0

Re: PS - Tree increasing every year, [#permalink]

### Show Tags

11 Sep 2007, 20:39
ashkrs wrote:
Had to guess on this one since time was running and I was wasting my time solving this.
Some easy steps?

Little bit tricky...You need to read the problem carefully.

Ok, my take:

Let the rate of increment is r.
Original height is 4.

At the end of 1st year, height will be (4+r)
....
....

At the end of 4th year, height will be (4+4r)
....
....

At the end of 6th year, height will be (4+6r)

According to the problem, at the end of 6th year height of the tree will be 1/5 taller than what it was at the end of 4th year....

That means,

Height at the end of 6th year = height at the end of 4the year + 1/5(height at the end of 4the year)

=> 4+6r = (4+4r) + 1/5(4+4r)
=> 2r = 4/5(1+r)
=> 10r = 4+4r
=> 6r = 4
=> r = 4/6
=> r = 2/3

- Brajesh
CEO
Joined: 29 Mar 2007
Posts: 2583
Followers: 19

Kudos [?]: 341 [0], given: 0

Re: PS - Tree increasing every year, [#permalink]

### Show Tags

11 Sep 2007, 21:15
ashkrs wrote:
Had to guess on this one since time was running and I was wasting my time solving this.
Some easy steps?

I had this same problem on my GMATPrep 1. Had to guess. I tried using the rate formula to solve this (which I could have), but the rate method made the setup unnessicarily complicated. So I had to move on and guess. Afterwards, I got it in a couple of min w/o tryin the rate formula... owell.

Heres the solution. Make the two years equal eachother in algebraic terms.

Since year 6 is 1/5 taller. Then it is greater than year four by 20%.
X is the growth rate. and then number next to X represents the years.
120/100(4+4x) = 4+6x ---> 6/5(4+4x)=4+6x

24/5+24x/5=4+6x ---> 24/5-20/5=30x/5-24x/5 ---> 4/5=6x/5

x=2/3.
GMAT Club Legend
Joined: 07 Jul 2004
Posts: 5062
Location: Singapore
Followers: 29

Kudos [?]: 281 [0], given: 0

### Show Tags

11 Sep 2007, 23:23
Fastest way is to just write down on the scratch pad the following:

Each year grow by x ft.

Start: 4ft
End of year 1: 4+x
End of year 2: 4+2x
End of year 3: 4+3x
End of year 4: 4+4x
End of year 5: 4+5x
End of year 6: 4+6x

1/5(4+4x) + 4+4x = 4+6x
x = 2/3
Director
Joined: 08 Jun 2007
Posts: 583
Followers: 2

Kudos [?]: 87 [0], given: 0

Re: PS - Tree increasing every year, [#permalink]

### Show Tags

12 Sep 2007, 07:39
Thanks all . You made it sound easy.
I was still struggling with verbage.
Manager
Joined: 12 Jun 2006
Posts: 55
Followers: 1

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

### Show Tags

28 Nov 2007, 22:44
ywilfred wrote:
Fastest way is to just write down on the scratch pad the following:

Each year grow by x ft.

Start: 4ft
End of year 1: 4+x
End of year 2: 4+2x
End of year 3: 4+3x
End of year 4: 4+4x
End of year 5: 4+5x
End of year 6: 4+6x

1/5(4+4x) + 4+4x = 4+6x
x = 2/3

Thanks guys!!...I recently got it in my gmatprep test too. Had to guess on it and got it wrong. But now it's clear as a crystal!
CIO
Joined: 09 Mar 2003
Posts: 463
Followers: 2

Kudos [?]: 42 [0], given: 0

### Show Tags

29 Nov 2007, 20:32
ywilfred wrote:
Fastest way is to just write down on the scratch pad the following:

Each year grow by x ft.

Start: 4ft
End of year 1: 4+x
End of year 2: 4+2x
End of year 3: 4+3x
End of year 4: 4+4x
End of year 5: 4+5x
End of year 6: 4+6x

1/5(4+4x) + 4+4x = 4+6x
x = 2/3

I did it the same way. My only change is very minor, but time saving:

1/5 more is the same as 6/5 of... so i immediately wrote:
4 + 6xx = 6/5(4 + 4x)

kinda nit-picky, but applied to multiple problems throughout the test could save a lot of time.
Display posts from previous: Sort by