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 Your Progress

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.

It appears that you are browsing the GMAT Club forum unregistered!

Signing up is free, quick, and confidential.
Join other 350,000 members and get the full benefits of GMAT Club

Registration gives you:

Tests

Take 11 tests and quizzes from GMAT Club and leading GMAT prep companies such as Manhattan GMAT,
Knewton, and others. All are free for GMAT Club members.

Applicant Stats

View detailed applicant stats such as GPA, GMAT score, work experience, location, application
status, and more

Books/Downloads

Download thousands of study notes,
question collections, GMAT Club’s
Grammar and Math books.
All are free!

Thank you for using the timer!
We noticed you are actually not timing your practice. Click the START button first next time you use the timer.
There are many benefits to timing your practice, including:

When a certain tree was first planted, it was 4 feet tall, [#permalink]
28 Jan 2008, 15:29

When a certain tree was first planted, it was 4 feet tall, and the height of the tree increased by a constant amount each year for the next 6 years. At the end of 6th year, the tree was 1/5 taller than it was at the end of the 4th year. By how many feet did the height of the tree increase each year?

Re: GMATprep : Height of the tree [#permalink]
28 Jan 2008, 18:03

GHIBI wrote:

When a certain tree was first planted, it was 4 feet tall, and the height of the tree increased by a constant amount each year for the next 6 years. At the end of 6th year, the tree was 1/5 taller than it was at the end of the 4th year. By how many feet did the height of the tree increase each year?

Could you please explain in detail?

Detailed answer.

annual fixed length: x length when planted: 4

year 1: 4+x year 2: 4+2x year 3: 4+3x year 4: 4+4x year 5: 4+5x year 6: 4+6x

so (4+6x)=4+4x+(4+4x)/5 (4+6x)*5=24+24x 20+30x=24+24x 6x=4 x=2/3

Re: GMATprep : Height of the tree [#permalink]
28 Jan 2008, 18:15

1

This post received KUDOS

GHIBI wrote:

When a certain tree was first planted, it was 4 feet tall, and the height of the tree increased by a constant amount each year for the next 6 years. At the end of 6th year, the tree was 1/5 taller than it was at the end of the 4th year. By how many feet did the height of the tree increase each year?

Could you please explain in detail?

The tree's growth is an arithmetic sequence since the growth is constant.

a(n) = a0 + nd, where d is the difference we are looking for and a0 = 4

a(6) = 4 + 6d and a(4) = 4 + 4d, and we know that a(6) = 1.2a(4)

4 + 6d = 1.2(4 + 4d) ---> 1.2d = 0.8 ---> d = 2/3 ft or 8 inches growth per year

Re: GMATprep : Height of the tree [#permalink]
28 Jan 2008, 18:23

GHIBI wrote:

When a certain tree was first planted, it was 4 feet tall, and the height of the tree increased by a constant amount each year for the next 6 years. At the end of 6th year, the tree was 1/5 taller than it was at the end of the 4th year. By how many feet did the height of the tree increase each year?

Could you please explain in detail?

original height of tree = 4 feet height gained in the past 6 years = 1/5th of the original height = (1/5) * 4 feet = 0.8 feet height gained EACH YEAR = 0.8 / 6 = 0.133 feet _________________

Re: GMATprep : Height of the tree [#permalink]
28 Jan 2008, 19:44

incognito1 wrote:

GHIBI wrote:

When a certain tree was first planted, it was 4 feet tall, and the height of the tree increased by a constant amount each year for the next 6 years. At the end of 6th year, the tree was 1/5 taller than it was at the end of the 4th year. By how many feet did the height of the tree increase each year?

Could you please explain in detail?

original height of tree = 4 feet height gained in the past 6 years = 1/5th of the original height = (1/5) * 4 feet = 0.8 feet height gained EACH YEAR = 0.8 / 6 = 0.133 feet

It's gained 1/5 of the height from year 4 to year 6, not from year 0 to year 6.

Re: GMATprep : Height of the tree [#permalink]
28 Jan 2008, 20:32

sonibubu wrote:

incognito1 wrote:

GHIBI wrote:

When a certain tree was first planted, it was 4 feet tall, and the height of the tree increased by a constant amount each year for the next 6 years. At the end of 6th year, the tree was 1/5 taller than it was at the end of the 4th year. By how many feet did the height of the tree increase each year?

Could you please explain in detail?

original height of tree = 4 feet height gained in the past 6 years = 1/5th of the original height = (1/5) * 4 feet = 0.8 feet height gained EACH YEAR = 0.8 / 6 = 0.133 feet

It's gained 1/5 of the height from year 4 to year 6, not from year 0 to year 6.

sonibubu, you're right -- it's comparing 6th year to 4th year, so an arithmetic sequence was required _________________

Re: GMATprep : Height of the tree [#permalink]
29 Jan 2008, 19:05

Agree with Ravshonbek. 2/3 is the answer.

Starts at 4ft year 1 4+n year 2 4+n+n year...

Two equations... 4+4n =x 4+6n = 1/5x + x

Solve for n. n = 2/3

Ravshonbek wrote:

GHIBI wrote:

When a certain tree was first planted, it was 4 feet tall, and the height of the tree increased by a constant amount each year for the next 6 years. At the end of 6th year, the tree was 1/5 taller than it was at the end of the 4th year. By how many feet did the height of the tree increase each year?

Could you please explain in detail?

Detailed answer.

annual fixed length: x length when planted: 4

year 1: 4+x year 2: 4+2x year 3: 4+3x year 4: 4+4x year 5: 4+5x year 6: 4+6x

so (4+6x)=4+4x+(4+4x)/5 (4+6x)*5=24+24x 20+30x=24+24x 6x=4 x=2/3

Re: GMATprep : Height of the tree [#permalink]
30 Jan 2008, 10:13

GHIBI wrote:

When a certain tree was first planted, it was 4 feet tall, and the height of the tree increased by a constant amount each year for the next 6 years. At the end of 6th year, the tree was 1/5 taller than it was at the end of the 4th year. By how many feet did the height of the tree increase each year?

How the growth of emerging markets will strain global finance : Emerging economies need access to capital (i.e., finance) in order to fund the projects necessary for...

One question I get a lot from prospective students is what to do in the summer before the MBA program. Like a lot of folks from non traditional backgrounds...