Last visit was: 24 Apr 2026, 01:06 It is currently 24 Apr 2026, 01:06
Home
Messages
Tests
Schools
Events
Close
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
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.
Go to My Error Log Learn more
Close
Request Expert Reply
Confirm Cancel
Back to Forum
Create Topic
805+ (Hard)|   Algebra|   Exponents|      
User avatar
Bunuel
User avatar
Math Expert
Joined: 02 Sep 2009
Last visit: 23 Apr 2026
Posts: 109,802
Own Kudos:
810,909
 [2]
Given Kudos: 105,868
Products:
GMAT Club Tests Forum Quiz
Expert
Expert reply
Active GMAT Club Expert! Tag them with @ followed by their username for a faster response.
Posts: 109,802
Kudos: 810,909
 [2]
If a^x*b^y = 200, where a, b, x, y are positive integers, x + y = ? 14 Jun 2018, 21:13
Kudos
Add Kudos
2
Bookmarks
Bookmark this Post
00:00
Start Timer
Pause Timer
Resume Timer
Show Answer
Hide
Show
History
E
Be sure to select an answer first to save it in the Error Log before revealing the correct answer (OA)!

Difficulty:

95% (hard)

Question Stats:

32% (02:09) correct 68% (01:38) wrong based on 69 sessions

History

Date
Time
Result
Not Attempted Yet
If \(a^x*b^y = 200\), where a, b, x, y are positive integers, x + y = ?


(1) x > y

(2) xy = 6
ShowHide Answer
Official Answer
E
User avatar
tejyr
User avatar
Joined: 26 Dec 2017
Last visit: 24 Dec 2021
Posts: 111
Own Kudos:
95
Given Kudos: 109
Products:
My Reviews
Posts: 111
Kudos: 95
If a^x*b^y = 200, where a, b, x, y are positive integers, x + y = ? 14 Jun 2018, 21:26
Kudos
Add Kudos
Bookmarks
Bookmark this Post
IMO it is B.
as per initial q, we can 2^1*100^1,2^3*5^2 or 50^1*2^2 and so on...
(1) x>y
2^3*5^2 [3+2] or 50^1*2^2 [1+2]
(2) xy=6
only one 2^3*5^2 [3+2]

Hence B
avatar
GMATisLovE
avatar
Joined: 06 Aug 2017
Last visit: 15 Aug 2020
Posts: 59
Own Kudos:
47
Given Kudos: 36
GMAT 1: 570 Q50 V18
GMAT 2: 610 Q49 V24
GMAT 3: 640 Q48 V29
GMAT 3: 640 Q48 V29
Posts: 59
Kudos: 47
If a^x*b^y = 200, where a, b, x, y are positive integers, x + y = ? 14 Jun 2018, 21:29
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Bunuel
If \(a^x*b^y = 200\), where a, b, x, y are positive integers, x + y = ?


(1) x > y

(2) xy = 6
Show more

Hi Bunuel

I have a doubt.

Do we even need statement I and/or II ?

\(a^x*b^y = 200 = 2^3*5^2\) , as a, b, x, y are positive integers

clearly x=3 and y=2, x+y = 5
User avatar
tejyr
User avatar
Joined: 26 Dec 2017
Last visit: 24 Dec 2021
Posts: 111
Own Kudos:
95
 [1]
Given Kudos: 109
Products:
My Reviews
Posts: 111
Kudos: 95
 [1]
If a^x*b^y = 200, where a, b, x, y are positive integers, x + y = ? 14 Jun 2018, 21:38
1
Kudos
Add Kudos
Bookmarks
Bookmark this Post
GMATisLovE
Bunuel
If \(a^x*b^y = 200\), where a, b, x, y are positive integers, x + y = ?


(1) x > y

(2) xy = 6

Hi Bunuel

I have a doubt.

Do we even need statement I and/or II ?

\(a^x*b^y = 200 = 2^3*5^2\) , as a, b, x, y are positive integers

clearly x=3 and y=2, x+y = 5
Show more

You missed some of the other possiblities:

\(a^x*b^y = 200 = 8^1*5^2 [x+y=3] or 10^1*20^1 [2]\)
User avatar
pr3mk5
User avatar
Joined: 01 Jan 2018
Last visit: 10 Aug 2018
Posts: 39
Own Kudos:
78
 [2]
Given Kudos: 10
Posts: 39
Kudos: 78
 [2]
If a^x*b^y = 200, where a, b, x, y are positive integers, x + y = ? 14 Jun 2018, 22:07
2
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Statement 1: x > y

2^3 * 5 ^2 = 200

x + y = 5

10^2 * 2^1

X + Y = 3.

No clear solution.


Statement 2: xy = 6

200^1 * 1^6 = 200.

x+y = 7

or

2^3 * 5^2 = 200
x+y = 5

no clear solution.

Combining both also :

we won't have a clear solution as
1^6*200^1 = 200.

x+y = 7

or

2^3 * 5^2 = 200
x+y = 5

In both cases x > y and x*y = 6.

OA - E.
User avatar
alldaytestprep
User avatar
Joined: 08 May 2018
Last visit: 24 Apr 2023
Posts: 98
Own Kudos:
108
Given Kudos: 1
Affiliations: All Day Test Prep
Location: United States (IL)
Schools: Booth '20 (A)
GMAT 1: 770 Q51 V49
GRE 1: Q167 V167
GPA: 3.58
Expert
Expert reply
Schools: Booth '20 (A)
GMAT 1: 770 Q51 V49
GRE 1: Q167 V167
Posts: 98
Kudos: 108
If a^x*b^y = 200, where a, b, x, y are positive integers, x + y = ? 15 Jun 2018, 09:19
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Bunuel
If \(a^x*b^y = 200\), where a, b, x, y are positive integers, x + y = ?


(1) x > y

(2) xy = 6
Show more

Statement 1:
Example 1: 200 = 100 * 2 = \(10^2 * 2^1\) ---> x+y = 3
Example 2: 200 = 8 * 25 = \(2^3 * 5^2\) -----> x+y = 5

INSUFFICIENT

Statement 2:
Example 1: x =3, y =2 ------> 200 = \(2^3 * 5^2\) ---------> x + y = 5
Example 2: x = 6, y = 1 ------> 200 = \(1^6 * 200^1\) -------> x + y = 7

INSUFFICIENT


Statements 1 & 2 Together:
The two examples from statement 2 work for the two statements combined.

INSUFFICIENT

Answer: E
User avatar
Bob2018
User avatar
Joined: 03 Apr 2018
Last visit: 13 Nov 2022
Posts: 52
Own Kudos:
9
Given Kudos: 70
Location: United Arab Emirates
Schools: ISB '20 Schulich Jan 2019 Entry
GMAT 1: 700 Q49 V35
GPA: 4
Products:
My Reviews
Schools: ISB '20 Schulich Jan 2019 Entry
GMAT 1: 700 Q49 V35
Posts: 52
Kudos: 9
If a^x*b^y = 200, where a, b, x, y are positive integers, x + y = ? 15 Jun 2018, 09:42
Kudos
Add Kudos
Bookmarks
Bookmark this Post
should be B.

from 1 we get 2 values of each x and y...
Moderators:
Bunuel
Math Expert
109802 posts
kingbucky
498 posts
Gmat860sanskar
212 posts