It is currently 20 Apr 2019, 22:13

### 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

# 2^30 - 2^29/2

Author Message
TAGS:
Founder
Joined: 18 Apr 2015
Posts: 6200
Followers: 99

Kudos [?]: 1199 [0], given: 5709

2^30 - 2^29/2 [#permalink]  07 Sep 2017, 14:44
Expert's post
00:00

Question Stats:

56% (00:14) correct 44% (00:32) wrong based on 25 sessions
 Quantity A Quantity B $$\frac{2^{30} - 2^{29}}{2}$$ $$2^{28}$$

A)The quantity in Column A is greater.
B)The quantity in Column B is greater.
C)The two quantities are equal.
D)The relationship cannot be determined from the information given.

Practice Questions
Question: 7
Page: 114
Difficulty: medium
[Reveal] Spoiler: OA

_________________
Founder
Joined: 18 Apr 2015
Posts: 6200
Followers: 99

Kudos [?]: 1199 [0], given: 5709

Re: 2^30 - 2^29/2 [#permalink]  07 Sep 2017, 14:52
Expert's post
Explanation

In quantity A we can simplify as follow

$$\frac{2^{29}(2^1 - 1)}{2}$$. From this we do have $$\frac{2^{29}}{2}$$

At this point put $$\frac{2^{29}}{2}$$ = $$2^{28}$$. Cross multiply $$2^{29} = 2^{28} * 2$$

At the end, we do have $$2^{29} = 2^{29}$$

_________________
GRE Instructor
Joined: 10 Apr 2015
Posts: 1647
Followers: 57

Kudos [?]: 1572 [1] , given: 8

Re: 2^30 - 2^29/2 [#permalink]  09 Sep 2017, 05:20
1
KUDOS
Expert's post
Carcass wrote:
 Quantity A Quantity B $$\frac{2^{30} - 2^{29}}{2}$$ $$2^{28}$$

Carcass' solution is probably how I would do this, but here's another approach:

Given:
Quantity A: (2^30 - 2^29)/2
Quantity B: 2^28

Multiply both quantities by 2 to get:
Quantity A: 2^30 - 2^29
Quantity B: (2^1)(2^28)

Simplify:
Quantity A: 2^30 - 2^29
Quantity B: 2^29

Quantity A: 2^30
Quantity B: 2^29 + 2^29

ASIDE: Quantity B features the sum of two identical values, which is the same as 2 times one value. For example, k + k = 2k, and 3w + 3w = (2)(3w)
So...

Simplify Quantity B to get:
Quantity A: 2^30
Quantity B: (2)(2^29)

Simplify again to get:
Quantity A: 2^30
Quantity B: 2^30

[Reveal] Spoiler:
C

RELATED VIDEOS

_________________

Brent Hanneson – Creator of greenlighttestprep.com

Re: 2^30 - 2^29/2   [#permalink] 09 Sep 2017, 05:20
Display posts from previous: Sort by