Divisible

This topic has expert replies
User avatar
Legendary Member
Posts: 643
Joined: Wed Aug 14, 2013 4:27 am
Thanked: 48 times
Followed by:7 members

Divisible

by vinay1983 » Sun Oct 06, 2013 8:35 am
If x, n, and m are positive integers and x/n = m, is x divisible by 3?

(1) m is divisible by 6.

(2) n is divisible by 15.
You can, for example never foretell what any one man will do, but you can say with precision what an average number will be up to!
Source: — Data Sufficiency |

GMAT/MBA Expert

User avatar
GMAT Instructor
Posts: 16207
Joined: Mon Dec 08, 2008 6:26 pm
Location: Vancouver, BC
Thanked: 5254 times
Followed by:1268 members
GMAT Score:770

by Brent@GMATPrepNow » Sun Oct 06, 2013 8:59 am
vinay1983 wrote:If x, n, and m are positive integers and x/n = m, is x divisible by 3?

(1) m is divisible by 6.

(2) n is divisible by 15.
Target question: Is x divisible by 3?

Given: x, n, and m are positive integers and x/n = m
This means that x = nm

Statement 1: m is divisible by 6
This means that m = 6k for some integer k
Since we already know that x = nm, we can write x = n(6k)
or x = n(2)(3)(k)
At this point, we can see that x is a multiple of 3, which means x is definitely divisible by 3.
Since we can answer the target question with certainty, statement 1 is SUFFICIENT

Statement 2: n is divisible by 15.
This means that n = 15j for some integer j
Since we already know that x = nm, we can write x = (15j)(m)
or x = (3)(5)(j)(m)
At this point, we can see that x is a multiple of 3, which means x is definitely divisible by 3.
Since we can answer the target question with certainty, statement 2 is SUFFICIENT

Answer = D

Cheers,
Brent
Brent Hanneson - Creator of GMATPrepNow.com
Image