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 500,000 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:

The average distance between the Sun and a certain planet is [#permalink]

Show Tags

15 Oct 2012, 04:36

Expert's post

7

This post was BOOKMARKED

00:00

A

B

C

D

E

Difficulty:

25% (medium)

Question Stats:

71% (02:27) correct
29% (01:24) wrong based on 889 sessions

HideShow timer Statistics

The average distance between the Sun and a certain planet is approximately 2.3 x 10^14 inches. Which of the following is closest to the average distance between the Sun and the planet, in kilometers? (1 kilometer is approximately 3.9 x 10^4 inches.)

(A) 7.1 x 10^8 (B) 5.9 x 10^9 (C) 1.6 x 10^10 (D) 1.6 x 10^11 (E) 5.9 x 10^11

Practice Questions Question: 65 Page: 161 Difficulty: 650

Re: The average distance between the Sun and a certain planet is [#permalink]

Show Tags

15 Oct 2012, 04:36

5

This post received KUDOS

Expert's post

5

This post was BOOKMARKED

SOLUTION

The average distance between the Sun and a certain planet is approximately 2.3 x 10^14 inches. Which of the following is closest to the average distance between the Sun and the planet, in kilometers? (1 kilometer is approximately 3.9 x 10^4 inches.)

(A) 7.1 x 10^8 (B) 5.9 x 10^9 (C) 1.6 x 10^10 (D) 1.6 x 10^11 (E) 5.9 x 10^11

The distance in kilometers would be: \(\frac{2.3*10^{14}}{3.9*10^4}\approx{\frac{23*10^{13}}{4*10^4}}\approx{6*10^9}\).

Re: The average distance between the Sun and a certain planet is [#permalink]

Show Tags

15 Oct 2012, 04:42

1

This post received KUDOS

Distance between the Sun and a certain planet in Inches = 2.3 x 10^14 1 kilometer = 3.9 x 10^4 inches Distance between the Sun and a certain planet in Km = (2.3 x 10^14)/ (3.9 x 10^4) = \((23/39) * 10^10\) = \((230/39) * 10^9\) = \(5.9 * 10^9\)

Answer B _________________

If you like my Question/Explanation or the contribution, Kindly appreciate by pressing KUDOS. Kudos always maximizes GMATCLUB worth-Game Theory

If you have any question regarding my post, kindly pm me or else I won't be able to reply

Re: The average distance between the Sun and a certain planet is [#permalink]

Show Tags

15 Oct 2012, 05:04

2

This post received KUDOS

Good question.

I took \(2.3 x 10^14\)and rounded down to \(2*10^14\), and took \(3.9*10^4\) and rounded up to \(4*10^4\).

Then, I did a unit conversion from Inches to Kilometers: \((2*10^14 Inches) * (\frac{1 Kilometer}{(4*10^4 Inches)})\)

Canceling out, we get \(\frac{(2*10^14 Inches)}{(4*10^4 Inches)}*1 Kilometer = 0.5*10^10 Kilometer\) or \(5*10^9 Kilometers\)

Since we rounded to begin with, we have to look for the solution that is both closest to our answer AND makes the most sense. In this case, the answer is

The average distance between the Sun and a certain planet is approximately 2.3 x 10^14 inches. Which of the following is closest to the average distance between the Sun and the planet, in kilometers? (1 kilometer is approximately 3.9 x 10^4 inches.)

(A) 7.1 x 10^8 (B) 5.9 x 10^9 (e) 1.6 x 10^10 (0) 1.6 x 10^11 (E) 5.9 x 10^11

Practice Questions Question: 65 Page: 161 Difficulty: 650

Each week we'll be posting several questions from The Official Guide for GMAT® Review, 13th Edition and then after couple of days we'll provide Official Answer (OA) to them along with a solution.

We'll be glad if you participate in development of this project: 1. Please provide your solutions to the questions; 2. Please vote for the best solutions by pressing Kudos button; 3. Please vote for the questions themselves by pressing Kudos button; 4. Please share your views on difficulty level of the questions, so that we have most precise evaluation.

Re: The average distance between the Sun and a certain planet is [#permalink]

Show Tags

19 Oct 2012, 04:56

1

This post received KUDOS

Expert's post

SOLUTION

The average distance between the Sun and a certain planet is approximately 2.3 x 10^14 inches. Which of the following is closest to the average distance between the Sun and the planet, in kilometers? (1 kilometer is approximately 3.9 x 10^4 inches.)

(A) 7.1 x 10^8 (B) 5.9 x 10^9 (C) 1.6 x 10^10 (D) 1.6 x 10^11 (E) 5.9 x 10^11

The distance in kilometers would be: \(\frac{2.3*10^{14}}{3.9*10^4}\approx{\frac{23*10^{13}}{4*10^4}}\approx{6*10^9}\).

Answer: B.

Kudos points given to everyone with correct solution. Let me know if I missed someone. _________________

Re: The average distance between the Sun and a certain planet is [#permalink]

Show Tags

22 Oct 2012, 09:04

Bro Bunuel, I wonder who you are and BB also declared you as the mystery man.. but you are doing an awesome job out here! thank you for all your help. My Question is

what if 6.1 x 10^9 is also one of the answer choices? what will your approach be in this case? _________________

hope is a good thing, maybe the best of things. And no good thing ever dies.

Re: The average distance between the Sun and a certain planet is [#permalink]

Show Tags

29 Jun 2014, 07:58

Hello from the GMAT Club BumpBot!

Thanks to another GMAT Club member, I have just discovered this valuable topic, yet it had no discussion for over a year. I am now bumping it up - doing my job. I think you may find it valuable (esp those replies with Kudos).

Want to see all other topics I dig out? Follow me (click follow button on profile). You will receive a summary of all topics I bump in your profile area as well as via email. _________________

Re: The average distance between the Sun and a certain planet is [#permalink]

Show Tags

11 Sep 2014, 01:27

Bunuel wrote:

The average distance between the Sun and a certain planet is approximately 2.3 x 10^14 inches. Which of the following is closest to the average distance between the Sun and the planet, in kilometers? (1 kilometer is approximately 3.9 x 10^4 inches.)

(A) 7.1 x 10^8 (B) 5.9 x 10^9 (C) 1.6 x 10^10 (D) 1.6 x 10^11 (E) 5.9 x 10^11

Practice Questions Question: 65 Page: 161 Difficulty: 650

Re: The average distance between the Sun and a certain planet is [#permalink]

Show Tags

29 Sep 2015, 06:15

Hello from the GMAT Club BumpBot!

Thanks to another GMAT Club member, I have just discovered this valuable topic, yet it had no discussion for over a year. I am now bumping it up - doing my job. I think you may find it valuable (esp those replies with Kudos).

Want to see all other topics I dig out? Follow me (click follow button on profile). You will receive a summary of all topics I bump in your profile area as well as via email. _________________

The average distance between the Sun and a certain planet is [#permalink]

Show Tags

25 Oct 2015, 18:02

Expert's post

schelljo wrote:

Will someone please help me explain how you get from \(\frac{6}{10}*10^9\) to the answer.

Thanks!

You are given that the distance is \(2.3*10^{14}\) inches. You need to convert this into equivalent distance in kilometers with the relation given as 1 km = \(3.9*10^4\) inches

Thus, by unitary method, if \(3.9*10^4\) inches equals 1 km, then \(2.3*10^{14}\) inches will equal = \(\frac{2.3*10^{14}}{3.9*10^4}\)

You can now assume \(2.3 \approx 2.4\) and \(3.9 \approx 4.0\) to make both the numbers divisible by a common factor (4 in this case).

The average distance between the Sun and a certain planet is [#permalink]

Show Tags

03 May 2016, 05:47

1

This post received KUDOS

Bunuel wrote:

The average distance between the Sun and a certain planet is approximately 2.3 x 10^14 inches. Which of the following is closest to the average distance between the Sun and the planet, in kilometers? (1 kilometer is approximately 3.9 x 10^4 inches.)

(A) 7.1 x 10^8 (B) 5.9 x 10^9 (C) 1.6 x 10^10 (D) 1.6 x 10^11 (E) 5.9 x 10^11

Practice Questions Question: 65 Page: 161 Difficulty: 650

This problem is a unit conversion with an added twist of scientific notation. We need to convert 2.3 x 10^14 inches to KILOMETERS. We are given that 1 kilometer is approximately 3.9 X 10^4 inches. We also should recognize that we are being asked which of the following is CLOSEST to the average distance between the Sun and the planet, in Kilometers. Because we are being asked for an approximation, we can use some estimation here.

To convert 2.3 x 10^14 inches to kilometers, we need to multiply 2.3 x 10^14 inches by the ratio of:

1 km/(3.9 x 10^4 inches)

However, before doing this multiplication, it will make things easier to clean up each scientific notation expression. Let’s start with 2.3 x 10^14 inches.

2.3 x 10^14 inches

is equivalent to

23 x 10^13 inches

Notice that because we turn 2.3 into 23, or move the decimal one place to the right, we have to then turn 10^14 into 10^13, or move the decimal one place to the LEFT to “counterbalance” the fact that we’ve moved the decimal one place to the right for 2.3.

Next we can adjust 3.9 x 10^4 inches. However, we can simply round this value up to 4 x 10^4 inches.

Since we’ve rounded 3.9 up to 4, let’s round 23 up to 24 also. That is, we are converting 24 x 10^13 inches into kilometers given that 1 km is approximately 4 x 10^4 inches:

(24 x 10^13 inches) x 1 km/(4 x 10^4 inches)

(24 x 10^13)/(4 x 10^4) km

We can break this work up into two separate calculations:

1) 24/4 = 6

2) 10^13/10^4 = 10^9

Thus, our answer is about 6 x 10^9 km.

We see that the closest answer is B. _________________

Jeffrey Miller Jeffrey Miller Head of GMAT Instruction

gmatclubot

The average distance between the Sun and a certain planet is
[#permalink]
03 May 2016, 05:47

Part 2 of the GMAT: How I tackled the GMAT and improved a disappointing score Apologies for the month gap. I went on vacation and had to finish up a...

Cal Newport is a computer science professor at GeorgeTown University, author, blogger and is obsessed with productivity. He writes on this topic in his popular Study Hacks blog. I was...

So the last couple of weeks have seen a flurry of discussion in our MBA class Whatsapp group around Brexit, the referendum and currency exchange. Most of us believed...