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

 It is currently 03 May 2015, 07:04

### 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

# Which of the following best approximates the value of q if

Author Message
TAGS:
Director
Joined: 10 Feb 2006
Posts: 664
Followers: 3

Kudos [?]: 121 [0], given: 0

Which of the following best approximates the value of q if [#permalink]  01 Nov 2007, 15:06
Which of the following best approximates the value of q if 528+311=5q ?

39
30
28
27
17
_________________

GMAT the final frontie!!!.

Manager
Joined: 02 Aug 2007
Posts: 146
Followers: 1

Kudos [?]: 14 [0], given: 0

Are you sure there isn't a typo here?

q is > 100
Director
Joined: 10 Feb 2006
Posts: 664
Followers: 3

Kudos [?]: 121 [0], given: 0

Correction --- [#permalink]  01 Nov 2007, 15:17
Which of the following best approximates the value of q if 5^28+3^11=5^q ?

39
30
28
27
17
_________________

GMAT the final frontie!!!.

Manager
Joined: 02 Aug 2007
Posts: 146
Followers: 1

Kudos [?]: 14 [0], given: 0

A. 39 is the best approx.
Director
Joined: 10 Feb 2006
Posts: 664
Followers: 3

Kudos [?]: 121 [0], given: 0

Which of the following best approximates the value of q if 5^28+3^11=5^q ?

39
30
28
27
17

My quick and dirty would be;

since 5 ^28 + 3 ^ 11 > 5 ^28 therefore the answer could be either 30 or 39

I would go with 30.
_________________

GMAT the final frontie!!!.

Director
Joined: 10 Feb 2006
Posts: 664
Followers: 3

Kudos [?]: 121 [0], given: 0

any more clues to get to the right answer without doing any calculations?
_________________

GMAT the final frontie!!!.

CEO
Joined: 29 Mar 2007
Posts: 2591
Followers: 16

Kudos [?]: 234 [0], given: 0

Re: Math - MGMT [#permalink]  01 Nov 2007, 15:22
Which of the following best approximates the value of q if 528+311=5q ?

39
30
28
27
17

From what I remember from these type of problems, you should completely ignore the 3^11.

So in that case q is equal to aprox. 28

C.

If not C then B, sry said D when I meant B.
VP
Joined: 28 Mar 2006
Posts: 1384
Followers: 2

Kudos [?]: 19 [0], given: 0

Re: Correction --- [#permalink]  01 Nov 2007, 18:10
Which of the following best approximates the value of q if 5^28+3^11=5^q ?

39
30
28
27
17

NOTE:
GMAT doesnt test your LOGARITHMS skill

Taking logs on both sides

28*log5 + 11*log3 = q*log5

Dividing by log5 throughout

28 + 12(appx) = q

12 appx 'cos loga to base a is 1 but if base is <a>1

Should be 39(appx)

Last edited by trivikram on 01 Nov 2007, 18:30, edited 2 times in total.
Director
Joined: 11 Jun 2007
Posts: 932
Followers: 1

Kudos [?]: 70 [0], given: 0

Re: Correction --- [#permalink]  01 Nov 2007, 18:26
Which of the following best approximates the value of q if 5^28+3^11=5^q ?

39
30
28
27
17

here is my take on the problem:

5^28+3^11=5^q
can be written in this way
5^28 + 3^3 * 3^3 * 3^2 = 5^q
3^3 = 27 close to 5^2, so...
5^28 + 5^2 * 5^2 * 3^2 = 5^q
so it's really 5^28 + 5^4 * 9 = 5^q
so answer is 5^28 + 625*9 (approx)
625*9 does not make a great impact when added to 5^28

i say the answer is q = 28
whats the OA??
Re: Correction ---   [#permalink] 01 Nov 2007, 18:26
Similar topics Replies Last post
Similar
Topics:
18 Which of the following best approximates the value of q if 17 23 Aug 2010, 08:32
Which of the following best approximates the value of q if 2 02 Nov 2008, 01:36
Which of the following best approximates the value of q if 4 28 Aug 2008, 15:28
2 Which of the following best approximates the value of q if 3 23 Jan 2008, 15:27
Which of the following best approximates the value of q if 12 08 Aug 2006, 17:43
Display posts from previous: Sort by