Last visit was: 23 Apr 2026, 14:39 It is currently 23 Apr 2026, 14:39
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.
Close
Request Expert Reply
Confirm Cancel
User avatar
Bunuel
User avatar
Math Expert
Joined: 02 Sep 2009
Last visit: 23 Apr 2026
Posts: 109,785
Own Kudos:
810,856
 [7]
Given Kudos: 105,853
Products:
Expert
Expert reply
Active GMAT Club Expert! Tag them with @ followed by their username for a faster response.
Posts: 109,785
Kudos: 810,856
 [7]
1
Kudos
Add Kudos
6
Bookmarks
Bookmark this Post
avatar
RossyJo
Joined: 05 May 2021
Last visit: 31 May 2021
Posts: 5
Own Kudos:
Given Kudos: 1
Posts: 5
Kudos: 1
Kudos
Add Kudos
Bookmarks
Bookmark this Post
User avatar
sujoykrdatta
Joined: 26 Jun 2014
Last visit: 22 Apr 2026
Posts: 587
Own Kudos:
1,191
 [2]
Given Kudos: 14
Status:Mentor & Coach | GMAT Q51 | CAT 99.98
GMAT 1: 740 Q51 V39
Expert
Expert reply
GMAT 1: 740 Q51 V39
Posts: 587
Kudos: 1,191
 [2]
1
Kudos
Add Kudos
1
Bookmarks
Bookmark this Post
User avatar
seikoholic
Joined: 04 Jul 2022
Last visit: 19 Feb 2023
Posts: 2
Given Kudos: 35
Posts: 2
Kudos: 0
Kudos
Add Kudos
Bookmarks
Bookmark this Post
sujoykrdatta
Bunuel
If x^2 + y^3 = 593 and y^2 = x + 55, then what is the value of x - y ?

A. 1
B. 2
C. 3
D. 4
E. 7

When the square of a number and the cube of a smaller number are added the result is 593. If the square of the smaller number exceeds the bigger number by 55, find the difference of the two numbers.

Assuming x and y are positive integers (the options for x-y are integers), we have:

y² = x + 55
Looking at squares of numbers greater than 55:
y² = 64 or 81 or 100 etc.
x = 64-55=9 or 81-55=26 or 100-55=45 etc.

We have:
x² + y³ = 593

If x = 9 => y³ = 593-81=512 => y = 8

If x = 26 => y³ < 0 i.e. y<0 - violates condition that y is positive.

Thus, we have: x=9 and y=8 => x - y = 1

Answer A

Note: If we try to solve by substituting x = y² - 55 in the first equation, we will get a 4th degree equation which is too complicated to solve (beyond the scope of the GMAT)

Posted from my mobile device

Could you please elaborate on the solution? It is very confusing to me. Thank you!
User avatar
Kinshook
User avatar
Major Poster
Joined: 03 Jun 2019
Last visit: 23 Apr 2026
Posts: 5,986
Own Kudos:
Given Kudos: 163
Location: India
GMAT 1: 690 Q50 V34
WE:Engineering (Transportation)
Products:
GMAT 1: 690 Q50 V34
Posts: 5,986
Kudos: 5,858
Kudos
Add Kudos
Bookmarks
Bookmark this Post
If x^2 + y^3 = 593 and y^2 = x + 55, then what is the value of x - y ?

x^2 / y^2 = {1,4,9,25,36,49,64,81,100,121,144,169,196,225,..}
y^3 = {1,8,27,64,125,216,343,512,...}

y^3 = 512; x^2 = 593-512 = 81; x = 9; y = 8; y^2 = 64; x = 9; y^2 = 64 = 9 + 55 = x+ 55

x - y = 9 - 8 = 1

IMO A
Moderators:
Math Expert
109785 posts
Tuck School Moderator
853 posts