Last visit was: 24 Jul 2024, 13:43 It is currently 24 Jul 2024, 13:43
Toolkit
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
Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here.

# 2−6/3 + 2−7/6 + 2−8/12 is how many times bigger than 2^−10?

SORT BY:
Tags:
Show Tags
Hide Tags
Math Expert
Joined: 02 Sep 2009
Posts: 94609
Own Kudos [?]: 643625 [11]
Given Kudos: 86737
Current Student
Joined: 24 Aug 2016
Posts: 726
Own Kudos [?]: 786 [5]
Given Kudos: 97
GMAT 1: 540 Q49 V16
GMAT 2: 680 Q49 V33
General Discussion
Tutor
Joined: 16 Oct 2010
Posts: 15148
Own Kudos [?]: 66848 [2]
Given Kudos: 436
Location: Pune, India
Intern
Joined: 29 Aug 2018
Posts: 28
Own Kudos [?]: 2 [0]
Given Kudos: 23
Re: 2−6/3 + 2−7/6 + 2−8/12 is how many times bigger than 2^−10? [#permalink]

"So our expression is 21/3 (= 7) times more than 2^{-10}"

Kindly, explain how you get 21/3?
Target Test Prep Representative
Joined: 14 Oct 2015
Status:Founder & CEO
Affiliations: Target Test Prep
Posts: 19191
Own Kudos [?]: 22718 [0]
Given Kudos: 286
Location: United States (CA)
Re: 2−6/3 + 2−7/6 + 2−8/12 is how many times bigger than 2^−10? [#permalink]
Bunuel wrote:
$$\frac{2^{−6}}{3} + \frac{2^{−7}}{6} + \frac{2^{−8}}{12}$$ is how many times bigger than $$2^{−10}$$?

A. 29/21

B. 3

C. 31/6

D. 7

E. 28/3

Simplifying, we have:

2^(-6) / 3 + (2^1)(2^(-8)) / 6 + (2^2)(2^(-10)) / 12

2^(-6) / 3 + 2^(-8) / 3 + 2^(-10) / 3

2^(-10) * (2^4 + 2^2 + 1) / 3

2^(-10) * 21 / 3

2^(-10) * 7

We see that the given expression is 7 times bigger than 2^(-10).

Intern
Joined: 11 Sep 2019
Posts: 17
Own Kudos [?]: 4 [0]
Given Kudos: 22
GMAT 1: 670 Q49 V33
Re: 2−6/3 + 2−7/6 + 2−8/12 is how many times bigger than 2^−10? [#permalink]
Bunuel wrote:
$$\frac{2^{−6}}{3} + \frac{2^{−7}}{6} + \frac{2^{−8}}{12}$$ is how many times bigger than $$2^{−10}$$?

A. 29/21

B. 3

C. 31/6

D. 7

E. 28/3

$$\frac{2^{−6}}{3} + \frac{2^{−7}}{6} + \frac{2^{−8}}{12}$$

$$2^{-8} * (\frac{4}{3} + \frac{2}{6} + \frac{1}{12}$$

$$2^{-8} * \frac{21}{12}$$

We know that $$2^{-10} = \frac{2^{-8}}{4}$$

So our expression is 21/3 (= 7) times more than 2^{-10}

Hi, I have a doubt, possibly a very stupid one,
If x=7y
isn't x 6 time more than y
Non-Human User
Joined: 09 Sep 2013
Posts: 34075
Own Kudos [?]: 853 [0]
Given Kudos: 0
Re: 2−6/3 + 2−7/6 + 2−8/12 is how many times bigger than 2^−10? [#permalink]
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: 2−6/3 + 2−7/6 + 2−8/12 is how many times bigger than 2^−10? [#permalink]
Moderator:
Math Expert
94609 posts