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

Redeem

If m is an integer, is m/102 an integer?

Expert replies
by VJesus12 » Sun Apr 28, 2019 10:07 am

Timer

00:00

Answers

A

B

C

D

E

Stats

Difficulty

If m is an integer, is m/102 an integer?

(1) 99 is a factor of 165m.
(2) 34 is a factor of 7m

[spoiler]OA=C[/spoiler]

Source: Veritas Prep
Join the discussion
Source: — Data Sufficiency |

by Ian Stewart » Mon Apr 29, 2019 3:18 am
Prime factorize: 102 = 2*51 = 2*3*17

So we can be certain m/102 is an integer if we can be certain m is divisible by 2, 3 and 17.

Statement 1 tells us 165m is divisible by 99, or that 165m/99 is an integer. So (33)(5m)/(33)(3) is an integer, and 5m/3 is an integer. That means the '3' in the denominator cancels somehow with something in the numerator, and since it can't cancel with the '5', it must cancel with something in 'm'. So m must be divisible by 3.

Similarly Statement 2 tells us 7m is divisible by 34 = (2)(17), which can only be true if m is divisible by 2 and 17.

So the two statements together ensure m is divisible by 2, 3 and 17 and the answer is C.
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