I would say A
With positive integer:
1) Sufficient
If you multiply Y by itself several times and get to a number X, of course, X is a multpile of Y...
E.g.: 3 * 2^2 + 7 * 2 = 12 + 14 = 26 --> 26 is a multiple of 2
(2) Not sufficient
With this one, we can still have both cases
X=3 --> x^2 - x = 9 - 3 = 6
--> Let's say Y = 3 --> OK, the answer (6) is a multiple of Y
--> X is a multiple of Y
--> Let's say Y = 6 --> OK, the answer (6) is a multiple of Y
--> X is NOT a multiple of Y
This would be my answer...
BREAKING: Target Test Prep releases Brand New 2026 On Demand GMAT prep course
Redeem
Target Test Prep GMAT OnDemand
Scott Woodbury-Stewart’s private virtual classroom — 400 hours of master-class video lessons for the GMAT Focus Edition.
- 715+ score guarantee — highest in the industry (99th percentile)
- 52 chapters · 1,500+ lessons · 4,000+ practice questions
- 400 hours of video · 1,500+ instructor-led HD smartboard lessons
- 300,000+ students accepted to Harvard, Stanford, Wharton, Booth & Sloan & more
- 24/7 live support + weekly Zoom office hours with GMAT instructors
- TTP AI Assist — 24/7 AI-powered virtual tutor for instant help
- 1,200+ flashcards + AI-powered study assistant & daily calendar
- OnDemand, LiveTeach & GMAT Bootcamp formats available
- Also: GRE, SAT Math & Executive Assessment courses
- MBA Admissions Consulting now available
- 🏆 2025 EdTech Breakthrough Award: Test Prep Solution Provider of the Year
- 200,000+ students served
- 5-day free trial — $0 to start, no auto-billing, cancel anytime
★★★★★
5.0
(559 reviews)
130-pt guarantee
$0 to start
then $127/mo
GMAT PREP?? ANOTHER ONE.
Source: Beat The GMAT — Problem Solving |
a) 3y^2+7y=x
y(3y+7)=x
since x and y are both integers, (3y+7) is an integer, say N.
we can say, y*N=x
Clearly N being an integer, (N times y)=x
Hence x is a multiple of y
SUFFICIENT
b) x^2-x is a multiple of y.
Or, Mx is a multiple of y. Clearly y is a multiple of x but nothing can be clearly said about x being a multiple of y.
NOT SUFFICIENT
My answer is A
Cheers!
Aks
y(3y+7)=x
since x and y are both integers, (3y+7) is an integer, say N.
we can say, y*N=x
Clearly N being an integer, (N times y)=x
Hence x is a multiple of y
SUFFICIENT
b) x^2-x is a multiple of y.
Or, Mx is a multiple of y. Clearly y is a multiple of x but nothing can be clearly said about x being a multiple of y.
NOT SUFFICIENT
My answer is A
Cheers!
Aks












