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
Live EA class + 6 months of EA OnDemand
  • Expert-led weekly online sessions
  • EA Masterclass access between classes
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.

130-point 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.

The positive two-digit integers x and y have the same digits

Expert replies
by BTGmoderatorDC » Sun Mar 03, 2019 5:08 am

Timer

00:00

Answers

A

B

C

D

E

Stats

Difficulty

The positive two-digit integers x and y have the same digits, but in reverse order. Which of the following must be a factor of x + y?

(A) 6
(B) 9
(C) 10
(D) 11
(E) 14

OA D

Source: Official Guide
Join the discussion
Source: — Problem Solving |

by Ian Stewart » Sun Mar 03, 2019 6:00 am
If AB is a two digit number, where A is the tens digit and B the units digit, then the number is equal to 10A + B.

Here we are adding AB and BA, which is the same as adding 10A+B and 10B + A. Adding those we get 11A + 11B, which clearly has 11 as a factor.
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 Brent@GMATPrepNow » Sun Mar 03, 2019 10:27 am
BTGmoderatorDC wrote:The positive two-digit integers x and y have the same digits, but in reverse order. Which of the following must be a factor of x + y?

(A) 6
(B) 9
(C) 10
(D) 11
(E) 14
Another approach is to test some values for x and y that satisfy the given information.

Positive two-digit integers x and y have the same digits, but in reverse order
So, it COULD be the case that x = 12 and y = 21

Which of the following must be a factor of x + y?
x + y = 12 + 21 = 33

Now check the answer choices...
(A) 6 is NOT a factor of 33. ELIMINATE
(B) 9 is NOT a factor of 33. ELIMINATE
(C) 10 is NOT a factor of 33. ELIMINATE
(D) 11 is a factor of 33. KEEP
(E) 14 is NOT a factor of 33. ELIMINATE

Answer: D

Cheers,
Brent
Brent Hanneson - Creator of GMATPrepNow.com
Image
Join the discussion