sanju09 wrote:If x is a positive integer divisible by 5, then which of the following could be the value of (x - 1) (x + 2) (x - 3) (x + 4)?
A. 54,260
B. 54,261
C. 54,262
D. 54,264
E. 54,265
Plug in increasing values for x and LOOK FOR A PATTERN.
If x=5, then (x - 1)(x + 2)(x - 3)(x + 4) =
4*7*2*
9.
If x=10, then (x - 1)(x + 2)(x - 3)(x + 4) = 9*
12*7*14.
If x=15, then (x - 1)(x + 2)(x - 3)(x + 4) = 14*17*
12*19.
If x=20, then (x - 1)(x + 2)(x - 3)(x + 4) = 19*22*17*
24.
In every case, the product is divisible by 12.
Thus, the correct answer choice must be a multiple of both 3 and 4.
For an integer to be a multiple of 4, its LAST TWO DIGITS must form a multiple of 4.
54,2
60
54,261
54,262
54,2
64
54,265
Eliminate every answer choice but A and D.
For an integer to be a multiple of 3, the SUM OF ITS DIGITS must be a multiple of 3.
A: 5+4+2+6+0 = 17.
Since 17 is not a multiple of 3, eliminate A.
The correct answer is
D.
Private tutor exclusively for the GMAT and GRE, with over 20 years of experience.
Followed here and elsewhere by over 1900 test-takers.
I have worked with students based in the US, Australia, Taiwan, China, Tajikistan, Kuwait, Saudi Arabia -- a long list of countries.
My students have been admitted to HBS, CBS, Tuck, Yale, Stern, Fuqua -- a long list of top programs.
As a tutor, I don't simply teach you how I would approach problems.
I unlock the best way for YOU to solve problems.
For more information, please email me (Mitch Hunt) at
[email protected].
Student Review #1
Student Review #2
Student Review #3
