LUANDATO wrote:If x = abc, is x/3 an integer?
(1) a, b, and c are consecutive integers.
(2) a < b < c
The OA is A.
Can any expert explain this DS question please? I don't understand it.
(1) a, b, and c are consecutive integers.
The product of three consecutive integers is divisible by 3. Sufficient.
See how.
Say the three consecutive integers are n, (n + 1), and (n + 2). Since an integer divisible by 3 will leave a reminder either 0, 1, or 2, we see that one among n, (n + 1), and (n + 2) will leave a reminder 0 upon being divided by 3. Thus abc is divisible by 3.
You may test with few examples. Sufficient.
(2) a < b < c
Case 1: a < b < c => 1 < 2 < 3. abc = 1*2*3 is divisible by 3.
Case 2: a < b < c => 1 < 2 < 4. abc = 1*2*4 is not divisible by 3.
Insufficient.
The correct answer:
A
Hope this helps!
-Jay
Download free ebook:
Manhattan Review GMAT Quantitative Question Bank Guide
_________________
Manhattan Review GMAT Prep
Locations:
New York |
Hyderabad |
Mexico City |
Toronto | and many more...
Schedule your free consultation with an experienced GMAT Prep Advisor!
Click here.
