BREAKING: Target Test Prep releases Brand New 2026 On Demand GMAT prep course

Redeem

Target Test Prep · GMAT

Choose how you want to prepare

Learn live with an expert or move at your own pace. Every option includes the complete TTP study system.

★★★★★5.0559 reviews
GMATLiveTeach 7 seats left
Chris Peckover
NEXT LIVE COHORT

Oct 13 to Jan 7, 2027

with Chris Peckover

Schedule
Tue, Thu · 8:00 to 10:00 PM ET
Included
40 live hours + 6 months of GMAT OnDemand
  • Live instruction and real-time questions
  • Class recordings and assigned practice
View class & enroll
Limited cohort · enrollment openTarget Test Prep
EALiveTeach 5 seats left
Logan Thompson
EXECUTIVE ASSESSMENT

Sep 6 to Dec 6, 2026

with Logan Thompson

Schedule
Sun · 9:30 AM to 12:30 PM ET
Included
40 hours of live online classes plus six months of access to the complete TTP EA OnDemand course.
  • 165+ EA Score Guarantee
  • 4,100+ Quant, Verbal, and Integrated Reasoning practice questions
  • 400+ hours of in-depth video lessons
  • 3,000+ step-by-step video solutions
View EA class & enroll
Limited cohort · enrollment openTarget Test Prep
GMATOnDemand Start anytime
SELF-PACED MASTERCLASS

Target Test Prep GMAT OnDemand

Complete access from day one. Study on your schedule.

715+ score guarantee
$0to start then $127/mo
  • Personalized study plan and analytics
  • Thousands of lessons and practice questions

Compare the format, schedule, and included access before enrolling. Prices and seat counts shown reflect the supplied offer details.

Problem from the MBA.com practice test 1

Expert replies
by pranavc » Thu Jul 03, 2008 7:57 pm
If n is a multiple of 5 and n=p^2*q, where p and q are prime numbers, which of the following must be a multiple of 25?

(A) p^2
(B) q^2
(C) pq
(D) p^2q^2
(E) p^3q

Any input on the above will be highly appreciated. Thanks in advance.
Join the discussion
Source: — Problem Solving |

by vishubn » Thu Jul 03, 2008 10:51 pm
Is the answer C) if yes :) this is how i solved it /...


Plug in values , I considered two prime numbers,
case 1) p=3 ,q=5

n=45 and also multiple of 5

plug in the same value in the answer choices .
a)p^2=9- eliminate
b)q^2=25 = keep it
c)pq=15= keep it
d) p^2q^2 =3^100 { now we know the repeating pattern of powers of three the unit digit is 3 which is not multiple of 3 ) = eliminate
e)p^3q =( the unit digit is 7 which is again not multiple of 5 ) =eliminate

now u r left with two options b and c

case 2) p=5 q=3
n=5^2*3
n=75 which is multiple of 5

go ahead and plug in the two options left
b)q^2=9 elliminate

C is the answer

Please Confirm the OA

p.s. this took me more than 2min any other shortcut :) much appreiciated
Join the discussion

by pranavc » Thu Jul 03, 2008 10:54 pm
The OA is D. I'm really sleepy right now so I will probably mull over solution when I wake up. I appreciate the prompt response.
Join the discussion

by vishubn » Thu Jul 03, 2008 11:21 pm
I goofed it up totalluyyyyy I was lookg for mutilple of 5 rather for 25 will come back on this sooon :)


Vishu
Join the discussion

by vishubn » Thu Jul 03, 2008 11:30 pm
I goofed it up totalluyyyyy I was lookg for mutilple of 5 rather for 25 will come back on this sooon :)


Vishu
Join the discussion

pranavc wrote:If n is a multiple of 5 and n=p^2*q, where p and q are prime numbers, which of the following must be a multiple of 25?
n is divisible by 5. n = p^2 * q, where p and q are primes. That is, n has only two distinct prime divisors, p and q, and one of them must be equal to 5. That is, either p = 5 or q = 5. Certainly p^2 * q^2 will be divisible by 5^2 = 25.

D.
For online GMAT math tutoring, or to buy my higher-level Quant books and problem sets, contact me at ianstewartgmat at gmail.com

ianstewartgmat.com
Join the discussion

by pranavc » Sun Jul 06, 2008 9:29 am
Thanks a lot for the explanation. My sincere apologies for not having acknowledged it earlier.
Join the discussion